Engine and trans swaps

[Mrfixit]

Hello all, finally got another 68 project charger! Pretty much a rolling shell that needs a ton of work...and parts. The vin suggests that it was a slant six from the factory, not sure if this was an option or not. Currently there is no engine or trans.Does have a v8 k frame though, so after thinking of what i want to put under the hood eventually, i need help/ suggestions. I know it's all dependant on what i'm doing with the car and how much i want to spend...  some of my questions for the car are things such as what engine and trans combos can i actually put in. Will later model stuff work in it? lets say for example, pulling a motor and trans from an early 90's dakota, or a mid 90's ram, or an 80's era rv...  Im thinking of stuff that is still kinda readily available.

[Troy]

That's pretty broad - but yes, you can put a whole range of stuff in there. It just depends on your wallet, skill, and tolerance for frustration. A Slant Six 68 Charger is extremely rare. However, that doesn't mean they are necessarily valuable so it doesn't sound like you'd ever get your money back if you restored it to factory stock condition. On to swaps...

The V8 k-frame was the same for big or small blocks (excluding Hemi - although after market motor mounts exist to even allow that). Since the car was manufactured with big or small block engines you can install either without making any modifications and with factory parts.

Big block:
The most popular swap will be a 440. They made these engines for a long time (1966?-1978) and they are reasonably priced. The 440 was the "performance" option and popular with racers so there are lots of factory upgrades and it is well supported through the after market. These came in large cars and trucks so not every 440 is a screamer right out of the box - but they are all essentially the same and if you're planning on a rebuild it doesn't matter what it was before you started. While these can also be found in motor homes, be careful that you aren't buying an "industrial" 413 or one that has the "extra cooling" because it will add a lot of extra work. You can generally find a 383 or 400 cheaper (possibly free) - and they will rev higher - but you'll need all the same parts as the 440 to install it in your car. If you plan on rebuilding/upgrading it's probably best start with the 440 as you have a cubic inch advantage. All these engines will bolt to the same factory 727 automatic transmission. When they were new, the manual transmission 440 cars would have come with an 18-spline 4-speed while the 383 got a 23-spline. These are pretty much identical from the outside but one handles more power. In 1968 the flywheel was 11" with 143 teeth but it's easy to install the later 10.5" 130 tooth flywheel and aluminum bell housing.

Old style "LA" small block:
These cars came with a 318 from the factory. These engines were produced for a very long time in large quantities. This was the default passenger car power plant through the late 60s and all of the 70s and was installed in police cars, taxi cabs, pickup trucks, and just about everything else. The early engines (especially 1968-1970) had pretty good power even with the small 2bbl carb. Chrysler also made a 340 (1968-1973) that could be found the performance models of the Dart, Challenger, Cuda, and later Chargers. It could be had with a 4bbl or Six Pack (1970 T/A and AAR). These are harder to find and expensive due to their desirability. After the 340's heyday it was replaced with the 360 which became a step up from the 318 through the 70s, 80s, and early 90s in cars and (mostly) trucks. Much like the big blocks, if you're tearing it down and building it from scratch it's best to start with a 360 for the larger cubic inches. Stroker kits are available for all three so you can come close to big block performance in the smaller, cheaper package. The 318 would have had the 904 automatic almost exclusively. The 340 cars came standard with a 727 - which was the same as the big block transmission but with a smaller bell housing. The small block 727 was available in some cars and most trucks through the late 70s at least and probably into the 80s in trucks but I'm fuzzy on that. Later versions picked up a locking torque converter so there's a few extra wires. The same 4-speed transmissions that fit the big block will also fit the small block as long as you have the right bell housing and linkage. Small blocks wouldn't have had an 18-spline from the factory. Whatever you choose, remember that the 360 is balanced differently so you have to have the matching torque converter or flywheel. The 340/360 motor mount is also slightly different and harder to find - but you can "shim" a 318 mount to make it work.

New(ish) small block:
After the "LA" family of engines, Chrysler rehashed the same basic design and came up with the "Magnum". It too was available in 318 (5.2 liter) and 360 (5.9 liter). These engines were available from
1992-2002 and, I believe, mostly or only in trucks. These engines have really good flowing heads,  roller cams, and EFI from the factory. Since they were based on the LA blocks they have all the same mounting provisions and will pretty much bolt in (and to) anything the earlier engines would. One distinct difference in that the intake to head mounting changed. You can remove the EFI and intake and change over to a carb but you'll need an intake designed to fit OR redrill an older version. Since the factory computer is such a pain there isn't a ton of after market support and most people just run a carb due to simplicity. You'll need to modify the fuel system for an electric pump even if you don't keep the EFI as there's no provision for a manual pump on the engine. Luckily, you can swap the front from an LA engine and add either a new cam with the fuel pump eccentric or just add a bolt on eccentric. This will also give you the old style accessory pulley ad belt system vs the Magnum's serpentine setup. If you keep the serpentine stuff I've read that the van power steering brackets are a better fit in our old cars. About this time, the automatic transmissions gained an overdrive gear. Much like the engines, the transmissions weren't completely new - just upgraded. Essentially the 904 became the A-500 and the 727 became the A-518. The overdrive control changed to electronic some time in the later 90s so most prefer the earlier ones for engine swaps. Once the transmission control went to the computer you pretty much have to swap both at the same time OR find a computer from a manual shifted truck if you want to keep the EFI. The tail is bigger so swapping one of these means building a new cross member and probably modifying the floor pan. The truck did come with various 5-speed manual transmissions but none easily fit into an old car. As mentioned, these will bolt to the older 4-speeds without issue. Once again, the 360 changed balance so you need the right torque converter or flywheel.

Even newer small block:
After the Magnum, Chrysler went to the modern 5.7 Hemi (trucks in 2003). Around 2005 they added MDS which gives the engine the ability to disable cylinders on the highway (saving fuel and reducing emissions). These engines are fairly reliant on the computer to make sure things work correctly but can be switched to run on a carb (although I think that's a waste). Moper Performance now sells a "swap" wiring harnesses and computer so these will work in old cars. The electronics can get very expensive very fast so keep that in mind when comparing. After the trucks, the Hemi became available in cars and those versions are easier to retrofit as the intakes are shorter. The 6.4, 392, 426 versions of this engine are the same size externally but can be very expensive. None of the transmissions attached to this engine from the factory will fit your car (easily that is). The good news is that the blocks - much like the Magnum series - retained all the previous mounting provisions so you can bolt them up to any old car or transmission. Again. the balance changed so use the correct parts.

Continued...

[Troy]

Mix and match:
Magnum heads will fit earlier LA engines if you redrill the block. This is a cheap way to get much better performance. You'll then need a Magnum style intake or a modified LA version. A 400 with a 440 crank nets 451 cubic inches with a real nice bore to stroke ratio AND a lower overall height. This means you can put on a taller intake without hitting the hood. The late 70s saw the addition of an overdrive gear to the 4-speed transmission (and, generally, an aluminum case as well). While these will bolt up to big or small blocks the same as the earlier models they are not as strong and unlikely to hold up to abuse. They are cheap and typically fit without modification so you could blow up several before reaching the price of the other options. Some people don't like the gear spread so the look to the after market. For a big block, there are kits to install a T-5 (basically Mustang) 5-speed. There are upgraded versions to handle the power from a 440. If you have a small block you can buy a bell housing and just install a Mustang transmission directly. These transmissions require modifications as they are larger and a "top loader" style so the shifter comes through the floor at a non-factory location. Keisler also makes a kit to install a GM overdrive automatic. Again, this requires floor modification. You can purchase a bell housing to put an A-500 or A-518 behind a big block but it requires cutting the front off your transmission. It's less modification to the car and you get overdrive. You can buy a Gear Vendors unit to add an overdrive to any early automatic or 4-speed transmission. Again, the tail shaft is significantly bigger then the original and require cross member and floor pan modification.

On anything, don't forget rear axle gears to match the rest of the drive train. A built 440 with a high stall torque converter and highway gears won't really do anything right. By the same token, a wimpy 318 with a stick shift and the right gear can be very surprising. By far the cheapest, most bang for the buck option is probably a late 60s 383 with 727 automatic transmission. Throw in some easily found 3.23 rear gears and it will be fun all around. The cheapest is probably 318/904. It can be fun (I had one) but the power output isn't rally worthy of a Charger. If you like to drive long distance or on the highway then you should really look at any of the overdrive options. If you hate adjusting carbs (like me) and want a fairly maintenance free experience then you'll want to avoid multi carb setups and may want to consider a modern engine or, at least, after market EFI. Be aware that this stuff gets expensive and you won't likely get your money back in fuel savings alone.

Troy

[Mrfixit]

Awesome! Thanks Troy, this is great info to have handy.

[miamivice]

That's pretty broad - but yes, you can put a whole range of stuff in there. It just depends on your wallet, skill, and tolerance for frustration. A Slant Six 68 Charger is extremely rare. However, that doesn't mean they are necessarily valuable so it doesn't sound like you'd ever get your money back if you restored it to factory stock condition. On to swaps...

The V8 k-frame was the same for big or small blocks (excluding Hemi - although after market motor mounts exist to even allow that). Since the car was manufactured with big or small block engines you can install either without making any modifications and with factory parts.

Big block:
The most popular swap will be a 440. They made these engines for a long time (1966?-1978) and they are reasonably priced. The 440 was the "performance" option and popular with racers so there are lots of factory upgrades and it is well supported through the after market. These came in large cars and trucks so not every 440 is a screamer right out of the box - but they are all essentially the same and if you're planning on a rebuild it doesn't matter what it was before you started. While these can also be found in motor homes, be careful that you aren't buying an "industrial" 413 or one that has the "extra cooling" because it will add a lot of extra work. You can generally find a 383 or 400 cheaper (possibly free) - and they will rev higher - but you'll need all the same parts as the 440 to install it in your car. If you plan on rebuilding/upgrading it's probably best start with the 440 as you have a cubic inch advantage. All these engines will bolt to the same factory 727 automatic transmission. When they were new, the manual transmission 440 cars would have come with an 18-spline 4-speed while the 383 got a 23-spline. These are pretty much identical from the outside but one handles more power. In 1968 the flywheel was 11" with 143 teeth but it's easy to install the later 10.5" 130 tooth flywheel and aluminum bell housing.

Old style "LA" small block:
These cars came with a 318 from the factory. These engines were produced for a very long time in large quantities. This was the default passenger car power plant through the late 60s and all of the 70s and was installed in police cars, taxi cabs, pickup trucks, and just about everything else. The early engines (especially 1968-1970) had pretty good power even with the small 2bbl carb. Chrysler also made a 340 (1968-1973) that could be found the performance models of the Dart, Challenger, Cuda, and later Chargers. It could be had with a 4bbl or Six Pack (1970 T/A and AAR). These are harder to find and expensive due to their desirability. After the 340's heyday it was replaced with the 360 which became a step up from the 318 through the 70s, 80s, and early 90s in cars and (mostly) trucks. Much like the big blocks, if you're tearing it down and building it from scratch it's best to start with a 360 for the larger cubic inches. Stroker kits are available for all three so you can come close to big block performance in the smaller, cheaper package. The 318 would have had the 904 automatic almost exclusively. The 340 cars came standard with a 727 - which was the same as the big block transmission but with a smaller bell housing. The small block 727 was available in some cars and most trucks through the late 70s at least and probably into the 80s in trucks but I'm fuzzy on that. Later versions picked up a locking torque converter so there's a few extra wires. The same 4-speed transmissions that fit the big block will also fit the small block as long as you have the right bell housing and linkage. Small blocks wouldn't have had an 18-spline from the factory. Whatever you choose, remember that the 360 is balanced differently so you have to have the matching torque converter or flywheel. The 340/360 motor mount is also slightly different and harder to find - but you can "shim" a 318 mount to make it work.

New(ish) small block:
After the "LA" family of engines, Chrysler rehashed the same basic design and came up with the "Magnum". It too was available in 318 (5.2 liter) and 360 (5.9 liter). These engines were available from
1992-2002 and, I believe, mostly or only in trucks. These engines have really good flowing heads,  roller cams, and EFI from the factory. Since they were based on the LA blocks they have all the same mounting provisions and will pretty much bolt in (and to) anything the earlier engines would. One distinct difference in that the intake to head mounting changed. You can remove the EFI and intake and change over to a carb but you'll need an intake designed to fit OR redrill an older version. Since the factory computer is such a pain there isn't a ton of after market support and most people just run a carb due to simplicity. You'll need to modify the fuel system for an electric pump even if you don't keep the EFI as there's no provision for a manual pump on the engine. Luckily, you can swap the front from an LA engine and add either a new cam with the fuel pump eccentric or just add a bolt on eccentric. This will also give you the old style accessory pulley ad belt system vs the Magnum's serpentine setup. If you keep the serpentine stuff I've read that the van power steering brackets are a better fit in our old cars. About this time, the automatic transmissions gained an overdrive gear. Much like the engines, the transmissions weren't completely new - just upgraded. Essentially the 904 became the A-500 and the 727 became the A-518. The overdrive control changed to electronic some time in the later 90s so most prefer the earlier ones for engine swaps. Once the transmission control went to the computer you pretty much have to swap both at the same time OR find a computer from a manual shifted truck if you want to keep the EFI. The tail is bigger so swapping one of these means building a new cross member and probably modifying the floor pan. The truck did come with various 5-speed manual transmissions but none easily fit into an old car. As mentioned, these will bolt to the older 4-speeds without issue. Once again, the 360 changed balance so you need the right torque converter or flywheel.

Even newer small block:
After the Magnum, Chrysler went to the modern 5.7 Hemi (trucks in 2003). Around 2005 they added MDS which gives the engine the ability to disable cylinders on the highway (saving fuel and reducing emissions). These engines are fairly reliant on the computer to make sure things work correctly but can be switched to run on a carb (although I think that's a waste). Moper Performance now sells a "swap" wiring harnesses and computer so these will work in old cars. The electronics can get very expensive very fast so keep that in mind when comparing. After the trucks, the Hemi became available in cars and those versions are easier to retrofit as the intakes are shorter. The 6.4, 392, 426 versions of this engine are the same size externally but can be very expensive. None of the transmissions attached to this engine from the factory will fit your car (easily that is). The good news is that the blocks - much like the Magnum series - retained all the previous mounting provisions so you can bolt them up to any old car or transmission. Again. the balance changed so use the correct parts.

Continued...

Thank you Troy for taking the time to write this up!   I am in the proccess of deciding what to do for an engine for a new project so this really help!   I am leaing toward a new(er) 5.9 magnum engine, and mating it up with a 4 speed.  Will see what I can find available out there (have nto started looking)

[Troy]

Something I just recently figured out: if you want to install a Magnum and keep the factory computer for EFI and ignition, many "tuner" type places can remove the automatic transmission checks if you can't find a PCM from a stick shift vehicle. Even if they don't take it out, the worst you get is a check engine light that always stays on. Originally I had been told that the PCM would go into "limp home" mode but it runs just fine. A positive side effect of this is that you can source an engine from something like a Durango which has a computer with many bells and whistles (4 windows, A/C, rear door opener, compass, outside temperature, etc.) but wasn't offered with a manual transmission. Of course, year and model have slight (or significant) differences so be sure to ask your preferred tuner up front if they can reprogram it the way you need.

Somewhere along the line (1998-1999?) the Magnum got 4 oxygen sensors so you'll need the same setup in your car. These aren't terribly expensive though ($29 each when I checked) so it's still less expensive than buying aftermarket EFI that doesn't require as many sensors.

Troy