Help me with my future build! 360 or 400

[chargd72]

This build won't start for a while but I'm starting to look out for good deals on a short block so I need to make a decision to move forward in a specific direction.  Right now the Charger has a built up 318 (lack of torque, go figure).  I have some parts (headers, air gap manifold, Mallory distributor, etc) that would bolt right on to an nicely built 408 stroker which is what I originally planned to do.  But I also have a tired 400 bb sitting in the Power Wagon that will need a rebuild soon.  Bone stock I'm already starting with good displacement and would be a great candidate for a stroker.  If I use the 400, I would need to get all new parts but then find something else to drop in the truck.  You see my dilemma?  I'm looking for a nice torquer for the street but also want reliability.  Any thoughts will help.  Thanks.

[Dino]

Start over, get a 440, have torque, be happy.   

[chargd72]

Start over, get a 440, have torque, be happy.   

Even if I get a 440, it will most likely need a rebuild.  So I might as well build up something for cheaper with parts I have, or build beyond a 440 with a block I have.

[Dino]

I can be totally wrong here but cheaper and stroker usually don't mix.  I see 440 blocks go for little money around Detroit and I know Troy, the site's owner has one or two complete ones for sale in the Cincinnati area.  Where are you located? 

I read an article once on modifying 318's and the results were pretty impressive, same with the 400 but I couldn't tell you what the better financial deal would be.  Of course with that small block you'd have more fun working on it as opposed to having a big block stuff the entire engine bay.

[chargd72]

Of course with that small block you'd have more fun working on it as opposed to having a big block stuff the entire engine bay.

Another reason I'm looking at just doing a stroked small block.  And believe me, I know any stroker won't be CHEAP, just cheaper due to some of the parts I already have that are reusable.  I'm down in Austin and don't see any cheap 440 blocks.  I see stock 318s going around here in the 4 digit range.  I come up to Detroit at least once a year, maybe the airline will let me carry it on???  

I've been doing some research and a lot of people seem to be liking the 470 stroker for street use and reliability.   

[randy73]

I vote 360, more parts available, which means cheaper.

If the 400 is low compression, I vote 400 and either a twin turbo or SC. Course you will have to build bottom end.

[Troy]

Interesting dilemma. You didn't say if you were on a budget - but these things always seem to hinge on money.

The stroker kits for a small block are cheap. Way cheap. You still have to pay for the machining and labor. You won't need to change many of the parts on your car that are unique to small block. This is the simplest approach.

If you take the 400 it's cheap - but now you have to replace it with something in order to make the truck mobile again which defeats the cost savings. You can make a 451 ci stroker out of it with a 440 crank which is probably the cheapest build out of all your options. A stock 400 will be a huge improvement over the 318 so don't get too carried away with maximizing power.

What transmission and rear end are in the car now? I'm assuming a 904 and something smaller than an 8 3/4"? If so, you're going to need to upgrade both if you throw a lot of power at it. That also means a new drive shaft. Brakes and upgraded fuel lines as well. A big block is heavier so you're going to want some stiffer springs to keep from sagging and wallowing down the road. You'll need a transmission, motor mounts, intake, carb, exhaust, and possibly hoses and other small items to make it work in the car.

If you've got the money to pay someone to build a 408 stroker then you can likely afford a 440. However, it's all the other stuff to install a big block that make the cost lopsided.

Here are a few other scenarios:
1. Buy a 360. Depending on the year it will have as much or more power than the 400 and will be lighter and bolt up with most of your existing parts. Be aware that the balance is different which requires a flex plate to match. You could also upgrade to a small block 727 at the same time so you're not replacing a busted transmission soon after. Maybe even get a later one with a lock up converter.

2. Buy a late model 5.2 or 5.9 Magnum. Take-out motors generally come with some sort of warranty. The heads are better than practically anything produced for the earlier LA engines and they're built to motivate big, heavy trucks (ie perfect for a big, heavy car). You'll likely save a few pounds and increase your mileage - especially if you keep the EFI. They respond well to minor modifications (intake, headers, cam) as well. The balancing issue applies here as well.

With most small block options you can build the engine without any down time to your car and the swap is a weekend (or even half day) affair.

3. Buy a 383. True, they aren't worth much (but neither is your 400) but that means you can generally find one that runs really well for a song. Make sure you get an early one from the muscle car years. Many times you can find them on Craigslist with a transmission attached. The 383/400 are shorter than the 440 so fitment issues with the intake are fewer. If you decide to stroke the 400 for your car one of these will drop right into the truck.

Troy

[chargd72]

Thanks Troy!

Yes, stock 904 with an 8 1/4 rear.  Already looking for parts on that swap too.  I'm going to put in a 727 with and 8 3/4 3.55.  That should do the trick.  With everything that you mentioned I think the better route is going to be the 408.  LIke you said, there are a few less mods necessary just for the car to handle a big block.  Also, I will be doing most of the build myself after the machine shop does all necessary block/head work so that could keep a coin or two in my pocket.  And when this is finished I can do a little warm up on the truck's 400.

Do you know if there are any pros/cons in using a magnum block vs la for a stroker? 

[Troy]

Not so much the block - but the heads are better. You can retrofit the LA block to work with the Magnum heads. I may have a set if you need them (I have aluminum ones for mine). The iron stockers are prone to cracking - although many people have used them like that and never had a problem. Nearly every one is cracked in the same spot so you'd think they were made like that from the factory. I haven't checked the ones on mine but the engine has less than 31k miles so hopefully they're mint...

Oh, Magnums were all fuel injected so you'll need the front end off the LA engine to use a manual pump (if switching to a carb). The cam is shorter as well and doesn't have a provision for the pump eccentric so you have to buy one (about $20) or swap in a better cam that has one built in. The Magnum engines all use the 360 pan so your 318 piece won't work (something on the 360 is larger - rear?). The 340/360 use different motor mounts than the 318 - although many people just add a spacer and claim it works fine. The Magnum engines have the new style and old style mounting provisions. There's a specific flex plate you can buy for the Magnum balance (or order the stroker kit with an internally balanced rotating assembly). LA headers fit Magnum heads so yours should bolt right up. The intake will not. I believe the bolts on the Magnum go straight down. You can modify the block to work.

Troy

[chargd72]

Thanks for the response troy, much appreciated.  I should have stated earlier that it doesn't have to be on an absolute cheap budget.  Since power is made in the heads I don't mind spending a little money on them.  Will probably go with a set of RHS aluminum heads.  I think those should work well on a stroker.  The air gap manifold I have has both straight and angle bolt holes for the heads so that can be interchangeable. I hear ya on the iron head cracking too.  I have a set of cast 302s on the 318 with with enlarged valves.  I heard they crack between the valves quite often so hopefully these will last the course of the 318.  Good info on the mechanical fuel pump.  Hadn't thought of that one.  Are mech fuel pumps sufficient to feed a 408?  I might just go ahead and look for an LA block so no cam previsions are needed.  And yes, will most likely be getting an internally balanced kit.

[Paul G]

I am in a similar situation as you are. I have a nice running 360, just want more power, and don't want to spend too much. Switching over to a 440 can yield nice power gains, but, switching everything over to a big block gets crazy. Seriously considering a take out 5.7, carbed. Still a small block, trans bolts up, makes nice power.

This month Mopar Muscle mag just did a crate engine comparison called "packaged power". The Blueprint 408 seems like a great deal. A stroker long block for $3595 (using Magnum iron heads). Assemble the rest reusing your own components. On there website they have other small block options like an "LA" 408 short block for $2195.

I must say that googling Blueprint engines brings up some scary read. Don't know whats real and what ain't?

[Wicked72]

supercharger from paxton

[Scaregrabber]

Heavy cars like big, torquey engines. It's just as cheap to build a 500 stroker 440 as it is a 408 stroker 360.

Sheldon

[magnumminded]

Don't feel bad. I am in the same boat at the moment unless I decide to trade or sell my 68 Coronet or a 71-74 Big Block B-Body. I have a bare bones car with 2.76 gears manual brakes and manual steering. Actually, I have the original 318 with 200k miles I think and the 904 just crapped out but, we're having issues with a stuck governor in the one I spent 1500 including the converter? It has a Summit K6900 camshaft kit, Cloyes double timing chain, Summit G9040 headers, Weiand 8007 intake, Mancini Racing Electronic Ignition Kit, Edelbrock 1406 carburetor. I traded a equal shape 79 LRE truck with a 5.9 Magnum swapped in place of the factory 360. In some ways I regret trading the truck because I really liked the torque of that 5.9 Magnum. It was a reman job with a stock cam and stock heads Air Gap intake with a Holley 600 cfm carburetor. The new owner ran it with the factory manifold logs and factory gearing. It ran a 15.1 @ 91 mph in a 4k truck.

Now, supposedly my 318 ran a 15.2 @ 92 mph with 100 lbs of stuff in the trunk.  It will be interesting to see what it will run since the one thing I have done with the 904 is have the low gearset installed. It basically it changes the gear ratios of the 1st and 2nd gearsets. So, factory was the same as a 727 at 2.45 1st and 1.45 2nd. The low gearset changes that to 2.74 1st and 1.74 2nd ratios. I also had the old factory converter changed to a PTC unit with a slightly higher stall and shift kit. Also, I think I had an intake leak so I got new gaskets and we shall see if it helps. I also had Dynomax Ultra Flo mufflers installed over the cheapy Summit Turbos.

Now, like you I did have a 400 big block/727 out of Newport but, sold it because like I said my dream weekend car is a 71 Charger with a 383/440. Now, I was told that even a modded 400 compared to my 318 would be a turd given the same without touching the pistons or heads. The BB 400 weighs around 150 lbs more not to mention that the true (not advertised compression)  is more like 7.5.1 because the pistons are more likely .080-.110 below deck vs the earlier 67-69 318s which are typically .050 below deck. The 904 is lighter I think by 40-50 lbs vs a 727 auto. You can have the low gearset installed in the BB 727 but, it costs more than the 904.

I think a 360 would be a great engine. But, if I were to build a stroker since you already have a small block I'd just do a 5.9 Magnum from a 92-03 truck/van so I could already have a roller cam and valve train. Plus you could use your current transmission as long as it is up to the task of handling the extra torque of a stroker engine. Also, I think the core shift and machining on the later engine would be better. With a Magnum engine you could get an eccentric to run a mechanical fuel pump but, I would just run an electric one as I know people who have problems the eccentric to run the mechanical pump.
The other benefit though I miss about the Magnum engine is that they are roller cam and roller lifters. Which means you don't have to worry about running a special zinc oil or additive vs the B/RB & LA engines with a flat tappet camshaft. Also, the rockers are 1.6 ratio but, I have heard of some guys using the I think the rockers from a Viper Engine? to get a 1.7 ratio. The 5.9 Magnum with a 600 carburetor and manifolds I would imagine is around 300 horsepower and 380 torque if I remember right.

If you already had a 440 is a great engine to have but, remember if you get one from 72 one the true compression will be around 7.2.1 to 7.8.1 without touching the pistons. I would choose a smogger 440 over a 400 for a performance application just because the 440 has more stroke and would cost the same to build as a 400 stroker engine. I mentioned earlier my dream car is a 71 Charger R/T with a 440. The reason why is because even though I am fairly young I like old school because that's what I grew up with. Heck even at 10 years old my dad's 72 Charger with a 77 400 ( stock heads, cam) 850 TQ, headers, and glasspacks was a fast car to me. Anyways, just my two cents.

[magnumminded]

One more thing to consider in the 360 vs 400 at least factory to factory. The 400 will be large bore and short stroke. The 400 has a stroke of 3.38 which isn't much more than 273,318, 340. A 360 will be closer to a 440 in stroke department. A 360 has a stroke of 3.58 vs the 440s 3.75 stroke.

[Cooter]

Unlike the 400, the 360 will have to have an aftermarket crank in order to gain more cubes..Not so with the 400...
Slam in a 440 crank for a 451-452 C.I. Beast with factory crank.

[Troy]

Unlike the 400, the 360 will have to have an aftermarket crank in order to gain more cubes..Not so with the 400...
Slam in a 440 crank for a 451-452 C.I. Beast with factory crank.

But stroker cranks for a 360/5.9 Magnum aren't a whole lot more expensive than an original forged 440 crank. You'll need rods, pistons, bearings, etc. as well. Complete small block Mopar stroker kits are ridiculously cheap. A great deal in my opinion.

Troy

[ACUDANUT]

" If you take the 400 it's cheap - but now you have to replace it with something in order to make the truck mobile again which defeats the cost savings"
Leave the truck alone and just find a 440.  Have you put a wanted add on Craigslist, for your area ?  I'll bet they are out there, around you.