how hard is this?

[mikes_classics_68]

hello everyone i dont post here much i usually just drool over everyones cars and try to gather information.
The question is, how hard is it to convert a 318 car to a big block car?
i am looking at a 68 318 and assuming i have the engine already and possibly a different trans, how hard or should i say "expensive would this conversion be? Unfortunately i don't posses the skill to do it myself so i would probably have a shop do it, any suggestions or guidelines or general info would be greatly appreciated  thanks alot!


   Mike

[Ghoste]

It isn't terribly hard at all.  As to cost, it depends of course on how much you have to replace and how NOS style perfect you want to go.  If you just want a bigger engine between the fenders, you get away pretty reasonably.

[Brock Samson]

i think it depends alot on two factors...
1. how much of the work you do yourself... being as shop time is $60-75 bucks an hour and up...
2. How Deluxe do you want the conversion to be... a simple 440 or 383 or a built 446 six-pack with a/c, disc brakes, TTI exhaust etc...
  like i'm trying to finish...     

[Joshua]

IF you have a trans and engine, and both are complete and running.....you could swap it all over in a day.....it's an easy drop in...

[Mike DC]

Assuming that matching-numbers values aren't high on your list and you just want an enjoyable fun car?

Then buy the car based on the sheetmetal's condition (rust & bondo) and the overall fit/finish of things.  Don't let a 318 car sway you away from an otherwise good car.  The swap costs a lot in mechanical parts, but it definitely beats bodywork.  The mechanical stuff is reversible at any point, it doesn't need to all be done at once, and the work is very quantifiable compared to other stuff.  (If you pay a shop to swap an engine, then either they did it or they didn't.  But the other kinds of work open up cans of worms about different opinions of "good" work, and you can get over your head about how much should all be done once the car has been torn down, etc.)

 

[chargerman68]

did it to mine no problem just finding a motor...thats all

also if u change out the motor u have to change trans,driveshaft,and rearend....

[Ghoste]

There may also be a little exhaust adapting but nothing that can't be readily overcome.  You may be okay with the rearend too, some of the 318 cars came with the good stuff.

[68chrgrwife]

we swapped the 318 for a 440, new tranny, new rearend, that's about it.  Don't see much else that would need to be done.

[dpm68]

If I can put a 355 Chev into my Toyota truck, then you can sure as heck drop a big block between the fenders of your ride...good luck!

[70charger_boy]

If you want to do a bb swap you have to do a full drivetrain swap.  That means you swap the 904 tranny for the 727 and the 8 1/4 rear for an 8 3/4 and possibly the drive shaft.  Also, the motor mounts will have to be fabbed on the kmember

[Dave22443]

No motor mount fab needed Charger Boy.  I put a 318 in my 68 as a temporary quick fix while I rebuilt my 440.  The ONLY THING I had to change (besides the motor) was the tranny and the driveshaft.  The 318 and the 440 fit the same K-frame perfectly and all the wires match up.  Only the mounts on the block are different and those are off the shelf parts. 

Oh, and I ran headers on both so the exhaust was not an issue.

[mikes_classics_68]

wow thanks for all the replys thiis has been very helpfull  i just want a driver and no a 318 has never swayed me away from a car i just wanted a fairly solid driver to tinker with to get it whre i want but also be able to drive it. the guy said it has a 8 3/4 rear end would that need to be replaced?

[69bronzeT5]

Yep, just like everyone said. Its pretty simple. Mine was a 318, its now a 383.

[Ghoste]

If you already have an 8.75 rearend, it should be capable of handling a 440.  Unless your planning on building up a monster. 

[Argos_Chargers]

Don't forget the radiator.  Odds are an old 318 radiator will have leakage and flow issues.  Buying a new big block 4 core radiator is well worth th emoney spent!  Too many people ruin their engines by overheating them.  Now that;s expensive! 

That's my $0.02...

[70charger_boy]

wow thanks for all the replys thiis has been very helpfull  i just want a driver and no a 318 has never swayed me away from a car i just wanted a fairly solid driver to tinker with to get it whre i want but also be able to drive it. the guy said it has a 8 3/4 rear end would that need to be replaced?

I don't know why you want to go through the trouble to do a swap.  I have a 318 in my 70 and it runs excellent and sounds mean.  It also gets 15 miles to the gallon, too

[rt green]

replace the fuel line with a 3\8 tube. you'll thank yourself for doing it

[Brock Samson]

  what exactly are your plans?.. and what do you have to work with?.. 

[Joshua]

I don't know why you want to go through the trouble to do a swap.  I have a 318 in my 70 and it runs excellent and sounds mean.  It also gets 15 miles to the gallon, too

All that trouble? It's NOT a big deal to swap.......I got 17 MPG with my 440 when travelling a long distance when it was stock....
Sounds mean eh??? But is it quick??? Nothing worse than having an old car that SOUNDS tough, but gets it's ass handed to 'em by Hondas.......
Chargers NEED Bigblocks....they're meant for each other!!!!  IMO..........

[70charger_boy]

I don't know why you want to go through the trouble to do a swap.  I have a 318 in my 70 and it runs excellent and sounds mean.  It also gets 15 miles to the gallon, too

All that trouble? It's NOT a big deal to swap.......I got 17 MPG with my 440 when travelling a long distance when it was stock....
Sounds mean eh??? But is it quick??? Nothing worse than having an old car that SOUNDS tough, but gets it's ass handed to 'em by Hondas.......
Chargers NEED Bigblocks....they're meant for each other!!!!  IMO..........

I drive real slow so I can see the look on people's faces.  It's also a good way to pick up chics

[Nacho-RT74]

The 318 and the 440 fit the same K-frame perfectly and all the wires match up.  Only the mounts on the block are different and those are off the shelf parts. 

Don't think the wires... Remember coil and dist are mounted in front on BB.

replace the fuel line with a 3\8 tube. you'll thank yourself for doing it

Not really necesary unless you gonna race. For street/strip 5/16 is simply enough.

If engine comes with all miscelaneous, you're pretty done, just take a look on radiator, exhaust fit, And of course all drivetrain stuff: BB matching Tranny or bellhousing if if was manual tranny. Axle would it be a nice upgrade if doesn't have at least 8 3/4, althought NOT MANDATORY.

Better also change T bars and sway bar however not necesary at first instance of change if you are tight on funds.

that's on all engines B bodies setup up 72. 73 and laters are another dff story.

[70charger_boy]

Nacho made an excellent point about the wires.  If the wire's under the hood look like frankensteins monster it would be good to replace the harness, instead of splicing 40 year old wires

[Jon Smith]

Quote from: rt green on Yesterday at 06:44:40 AM
replace the fuel line with a 3\8 tube. you'll thank yourself for doing it


Not really necesary unless you gonna race. For street/strip 5/16 is simply enough.

speaking from experience I'd do the fuel lines and add a decent street/strip fuel pump,
if the fuel supply isn't up to the job it'll be slower than it was with the 318

[miller]

i thought before people said i would have to replace the k-frame... i guess i bought extra parts for nothing?

[Mike DC]

   
The K-frame issue has been covered many, many times.  The confusion never stops because it depends on the model-year of car whether a SB/BB swap needs a new K-frame or not.  (And the changeover didn't happen at the same time as a total-body-restyle either, so the info can't just be shorthanded into "2nd-gens do this, and 3rd-gens do that," etc.)


On wedge-head motors in 2nd-gen cars, the answer is easy.  The same common K-frame works on every V8 motor (except the 426 Hemi) with just swapping the small bolted-on motor mounts.