331 or 408?

[My Cobra]

Well guys i am ready to do this. I have pulled my motor. I am going to make sure all is good with it. Re do all the seals and check it over. I am going to put it back in and spray it while i build my new motor. My question is 331 or 408? I want to stay EFI and i am going single turbo. I am going to have to get some machine work done on either, new H/C/I and bottom end. So what do you think take a 302 to a 331 or take a 351 to a 408? What are the ups and downs with each? Thanks guys. ~NICK~

[Blacksheep]

It really depends on your power goals, and what you wanna do. If your gonna drive the car pretty often then i say 331, im not sayin that you cant drive a 408 often, but damnit boy... If you wanna be diff, then go 408.

[My Cobra]

I am going to have to buy another 302 block if i decide to go 331 so i was thinking might as well go with a 351 and start from that point. Since the rest is going to be replaced anyway. thanks for the input. It will be a beast

[Blacksheep]

Why do you hafta buy a nother block? is yours messed up or something?

[Dave_R]

If you are going to stay with a stock production 90 era blocks don't waste your money on a stroker. Shoot if you are going to stay with a roller 302 I wouldn't upgrade the crank or rods. A good set of pistons and a good machinist is all that is needed. With a good tune and boost the stock block will let go before the stock rods or crank.

[nastynotchback1]

408.9.5 deck stock block is gonna last longer than the 8.2 and of course make more power.off the subject i was in franklin yesterday at the fun factory.

[Dave_R]

I do agree that the 9.5 deck will hold more power but I just don't see needing the stroker with a stock block on either case.

[greypony89]

I will tell you this if I had it to do over and I love my engine but what you have to spend to really make it right You might as well go all out go 408 or even 427 wish I would have now could have done for about the same money and had a couple hundered more horse power.

[Dave_R]

Don't get me wrong my engine build will consist of a 408 stroker but I am not going turbo again.

[XSR]

You have to determine your goals, budget, and use of the car. For the money vs dependable hp, the 351W comes out way ahead. Simply because as stated a good early model 351 can handle upwards of 800-1,000hp. To hold that in a 302 based motor, you will need a aftermarket type block. Then you also have factor in what you need to make the 351W work with what you have, or don't have.

[My Cobra]

so 408? I am going to get another block because i hate to take the motor i have strip it all off and not be able to use any of the parts. If i just buy a block and build it on a stand. I can drive the car i have. Then sell the motor running and complete when mine is done. That was my reasoning.

I am sorry that you made it to franklin. Ha ha just kidding. Next time you are this way let me know.

[My Cobra]

I would hate to build the 302 to a 331 dump a ton of money in it then turn up the boost later and split it. I was thinking a 351 i could pick up at a junk yard and not have a ton of money in it like a aftermarket 302.

[Star Driver]

Go BIG or go home.......:bat:

[My Cobra]

What do i look for when looking for a 351? Most of them are carb i want to swap them to EFI. What about the deck ?

[SmithRacing]

I built a 410 when I had the 95 Cobra.

[XSR]

What do i look for when looking for a 351? Most of them are carb i want to swap them to EFI. What about the deck ?

There really is'nt much to look for for efi, it will all bolt on. The only thing is if you are going hyd. roller, then you will need to do some simple work on the block, or you can buy drop in link bar hyd. roller lifters(pricey $400 or so). Let me know if you need any help, or advice.

[My Cobra]

ok sounds good. I am just unsure where to start. I know what i want just not sure how to get started. What would be the best bang for the buck on a 351 block ? Knowing it will be turbo. Hope to make around 6. ( Want to go with that block just so i don't have to worry about it cracking )

[XSR]

Pm me with your goals, and I can figureout what's the best route for you.

[SVTSkip]

408 all the way. I was faced with the same dilemma a little over a year ago, and went the wrong way. Now i have a nice all forged 302 with some great parts, AND I'm still going to do a 351 based stroker in the future. I coulda just done it once...

[Tusk]

remeber,the old saying"there's no replacement for displacement",i would for sure do the 351 build,now whether or not a 408 i doubt it,i would probably do a 393,or bore it a littel more and go a 396,that would get some attention when you tell people your fox has a 396 in it:yes1:the 351 i'm building is not going to be stroked,because i'm doing a budget build to see how much powere i can get on the cheap and with me being a gun guy i just had to have a 357

[My Cobra]

hell yea. That sounds sweet. Got any info on your build?

[93whitelxcoupe]

hell yea. That sounds sweet. Got any info on your build?


If you are planning to go turbo and are trying to do this on a "Budget", then find a Mexican block and build a 331.

[My Cobra]

If i stroke a 302 to a 331, buy new heads, new internals and have it all set up. the onlything i would be doing diffrant would be starting from a 351 instead of a 302 right? In the long run i am going to be spending about the same money ( obviously i would need to buy a 351 block out of some old truck or something ) Putting new heads, internals and machine work on it right? What am i missing here that will cost a lot more if i go with a 351 block and stroke.

[Tusk]

's OTE=My Cobra;15105]hell yea. That sounds sweet. Got any info on your build?[/QUOTE]

i started off with a early 351(i know everybody says they are junk,i seen a few 9 sec cars running these blocks,rpm's kill so keep under 6k,she'll live),a set of e-bay speedpro forged pistons 8.2 compression,a set of e-bay eagle rods,a small herbert hydraulic cam,a set procomp 190cc heads,a edelbrock torker intake, a 750 csu blow thru carb and a b-w s-400 turbo,also will be using meth injection and running somewhere between7-12 lbs of boost,from builds i have seen similar to mine they put down anywhere between 650-725 rwhp,but then again each engine is different so i might get surprised,may make more ,may make less

[93whitelxcoupe]

If i stroke a 302 to a 331, buy new heads, new internals and have it all set up. the onlything i would be doing diffrant would be starting from a 351 instead of a 302 right? In the long run i am going to be spending about the same money ( obviously i would need to buy a 351 block out of some old truck or something ) Putting new heads, internals and machine work on it right? What am i missing here that will cost a lot more if i go with a 351 block and stroke.


I just did the conversion to a 351W based combo, and let me tell you, there is a reason you do not see "EVERYONE" doing the conversion. Yes, in theory it should just drop right in like a 302 that needs a little more hood clearance, but how the statement is so far from the truth! It requires a lot more fabrication than people are actually willing to tell you about. Like I said if it where that easy, everyone that owned a mustang would have a 351W in them!

[My Cobra]

I just did the conversion to a 351W based combo, and let me tell you, there is a reason you do not see "EVERYONE" doing the conversion. Yes, in theory it should just drop right in like a 302 that needs a little more hood clearance, but how the statement is so far from the truth! It requires a lot more fabrication than people are actually willing to tell you about. Like I said if it where that easy, everyone that owned a mustang would have a 351W in them!

Care to explain what all i would be looking at changing? Anybody else have any input on this?

[My Cobra]

What year and what vech. would be a good car or truck to look for to pull the motor out of as far as the 351 goes?

[XSR]

I guess it's all on how you do it, but the 351W is actually a bolt-n motor. You can use the motor mounts, and the acc., though you do need the 351W lightning brackets. You need to oilpan, dist., and intake. The efi can run on the 351W as long as you use a 302HO cam, for the firing order.

If you want me to help with anything, or do any of the work, just let me know. I know we've discussed a few things in pm. So, just let me know.......


Greg

[My Cobra]

thanks greg. I am looking to do a lot of the work my self. I just picked up the car to learn what i could and do most of the work my self. I guess i have a lot of questions and get a lot of diffrant answers from all the people so it confuses the crap outta me. I have went thru what i can find on the net and it look to me like that 351 swap is not that big of a deal. You would need a new oil pan, dist, intake and heads which i am going to do anyway. Then i hear one company makes some better motor mounts that lower it a bit. I guess i will need a cowl hood also. So my question is where do i start? What truck or car do i need to hunt down to find a decent place to start from? I will get you guys to do some head work on whatever i decided to do.

[XSR]

Not a problem, I understand that. I have always done all my own work, from the very first tune/brake job, to all out race motors now. Pretty much all the early vehicles had the same 351W blocks. The 69's of course is the hardest to find, and is the strongest. The 70-74 modles are the next strongest ones. The new blocks went to less strength/materials for cost and weight savings, not to mention less nickle in them. If you can find a 84crown vic, police model, they have the dbl hump pan/pickup for the fox's. Otherwise the Motorsports are the same, and fairly reasonable on price(compared to the Moroso/Canton pans).