331 or 408

[00 Red SS]

I have a 331 stroker kit but havent started any machine work or anything on it right now its just parts in the shop. Everyone keeps trying to talk me into a 408, the shop will give me credit and get the equivilant but 408 parts if i want. The 331 or 408 shortblock will cost me the same but I cant friggin decide which way to go. It isnt my daily driver, pretty much my lil drag car with street tags. Only driven on the streets when i feel like it and weather permits. I havent bought the intake or heads so i dont have a commitment towards either so far.
Which one woulf you build and why?

 

[giddyup306]

408. Won't cost much more to build and there is no replacement for displacement. (ignore my sig)

 

[00 Red SS]

I am staying efi btw. I guess a 408 w/ afr 205's, and the rest wouldnt be bad either i just never put any thought towards it for some reason i just had 331 set in my mind. I was gonna change motor mounts, exhaust and that stuff out anyways.

 

[giddyup306]

Speaking of motor mounts you will need the lowering mounts if you want it to fit under the stock hood.

 

[00 Red SS]

No worries here, I have a 6" cowl back liftoff hood.

 

[90mustangGT]

I've been looking at the same thing myself. I will probally do a standard rebuild on my 302 but if I were to stroke it I would go with a 351 stroker because it will cost the same, except then I would have to change alot of things to make it fit and more things on top of that to feed all those cubes.

 

[9 Deuce GT]

I am in the middle of a 351w swap right now. If you want to swap to a Windsor based setup, just keep in mind all the extras you will need:

distributor
oil pan
intake
headers/exhaust system
heads
flywheel/balancer
roller lifters-if you chose that route
fuel injectors
accesory brakets
cooling system

There are others, but remeber you are swaping to a wider/taller block. There are many things to consider. If you are like me, and just want a sick setup, then this will be less of a concern. I am sure the eventuall power will be well worth it, but it's going to be relatively expensive. I'm not trying to discourage you from it, just be aware of the cost.

 

[bc474]

Why do you need different heads, injectors, cooling system, and lifters?

 

[00 Red SS]

331 or 408 i was still planning to get new heads afr 205's, new exhaust 1 3/4 longtubes, 3" xpipe, 3" 1ch flows, not sure on intake yet though, elect water pump so the only belt driven assec. i have is an alt, new oil pan, new msd distributor, sfi balancer. Also going to swap in a tremec so new clutch and flywheel were gonna be changed anyways. If i dont run out of money a upr kemember/a arm/coilover kit will also be going on.
Either way i go itll be expensive but i want to do it all right.

How much more cramped is the engine bay with a 408, does it make a plug change that difficult?

 

[bln92cpe]

Go with the 408..Unless you want a Blower then get the 331 or a 306. I got a 306 because I have the S trim, however mabye in a few years I am gonna go "all motor" and do the 408 thing..I bet it sounds so mean with a BIG lopey cam...Thats just what I want..Good luck.

 

[9 Deuce GT]

In order to get the potential out of the 351w based motor, you will deffinetly want bigger induction and exhaust parts. Fuel system will need upgrade. With this guy having the 42# injectors and big fuel pump, he should be alright. A bigger cooling system may not be neccesary if you don't sit in traffic, but if your car is a daily driver or see some miles a week, you will want better cooling to be safe. As far as lifters go, you coould stay with a flat tappet system, but if you want to run an off the shelf hyd. roller, you need to get link bar lifters.

 

[Jason@AFR]

grant it the 331 would be cheaper and easier, but if you look at the long run, blower or not, you may absorb of going big now over a year or to. Look at it this way, if you have the bigger motor, you don't have to push it as hard to get a certain amount of power as you would a samller motor, not having as much psi/N2O/RPM, will make your motor last longer. In other words, parts of a high-revving 331 may hit the pavement before an equally well-built lower RPM 408.

But if you are going all out and pushing any (or all ) of these, long term reliability is going to suck anyways, but big motor=big power.

Atleast you are going the correct route (AFR 205's ) either way, give me a call or PM me if you need any help, or suggestions with the rest of your combo.