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TexasEd

Stroke my 302 to 331 or Do a 351W/408 swap?

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I have a 69 Sportsroof with my original 302.  Once I'm done with cooling upgrades, interior and body I may address power. I think I would like to be in the 400-450 HP range and it would be nice to have a sub 11 second car.

I have a C4 with an 8" open differential.  Regardless of engine upgrade I would want a Traction-Lok 3rd member but 8" vs 9" is undecided (Is 9" essential after a certain torque rating?). Transmission is a secondary decision.

Staying with SBF Windsor V8 but want to know the pros and cons of:

a) Stroking my original 69 block 302 to 331 with new intake, heads, roller cam/lifter conversion, crank, pistons, etc.  Maybe going with Holley Sniper but happy to stay with regular carb.

b) Building up a roller 351W and maybe going to 408.

What are the cons of swapping to a 351 block?  What is the trade-off in price or other factors?  Really interested in people that have done this.  The people that have not seem to all say go 408 but one guy that has says go 331.

 

 

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2 hours ago, TexasEd said:

I have a 69 Sportsroof with my original 302.  Once I'm done with cooling upgrades, interior and body I may address power. I think I would like to be in the 400-450 HP range and it would be nice to have a sub 11 second car.

I have a C4 with an 8" open differential.  Regardless of engine upgrade I would want a Traction-Lok 3rd member but 8" vs 9" is undecided (Is 9" essential after a certain torque rating?). Transmission is a secondary decision.

Staying with SBF Windsor V8 but want to know the pros and cons of:

a) Stroking my original 69 block 302 to 331 with new intake, heads, roller cam/lifter conversion, crank, pistons, etc.  Maybe going with Holley Sniper but happy to stay with regular carb.

b) Building up a roller 351W and maybe going to 408.

What are the cons of swapping to a 351 block?  What is the trade-off in price or other factors?  Really interested in people that have done this.  The people that have not seem to all say go 408 but one guy that has says go 331.

 

 

 

to answer your first question: 

my current 392w stroker had a "street fighter" c4 from performance automatic with a 2500 stall convertor and I had stock open 3:00 diff, it was a good platform and nothing ever broke as I was on street tires. I would definitely look into performance automatic if you decided to stay with the c4 or you can buy their 4spd auto. I decided to go manual as that was the original goal, so I went with a TKO0600 and went with a trutrac ford 9 w/3:50 gears. I was able to put down 360rwhp and 400rwtq after dyno and tune.

if there was a 5-6 speed auto that could fit with no cutting/mods I would have gone this route.

For the 302/351w:

both 302//351w are great platforms, though the power you are wanting to make, I think the 331 should be easy build, but the 302 block has limitations if you are trying to achieve max power, thats when the 351w comes in to play, they can take up to 600hp no problem. 

price is roughly the same with both engines, with a 351w you are limited to intake options, if you stay with the stock hood, I wanted the edelbrock airgap but I read there was clearance issues with the stock hood and some ppl recommended going with a cowl hood. I went with the weiand stealth intake instead, to keep my stock hood and I make good power overall.

the 302's are easier to work on, they are smaller and no clearance issues, 

351w are somewhat wider and taller and can get tight under the hood if you go with big heads and headers, servicing the 351w can be tiresome, which is why some ppl tend to stay with a 302 but 351w can take more power. 

of course, these opinions can be eliminated if you went with a dart block, then I suggest going with the 331. 

 

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Seems like I've seen this thread before somewhere. But anyway..

When people say they want a bunch of power and there's a choice between a smaller engine and a bigger one, the answer is the bigger one. Pretty much just that simple.

Getting around 400 HP from a 351W isn't too hard. Stroke it for more. 

8 inch rears rule of thumb are good up to 400 HP or so if there's no drag racing with slicks. Sounds like you'll need a 9.

The "sub 11 second" thing kind of throws this. Such times aren't that easy to achieve. Plus if you do, they're going to say you have to have a roll cage if you plan to keep going to the track. Have a plan for that? 

An alternative to all this is to just hotrod the engine and car how you want to with an eye towards improving it's performance. If you forget about focusing on some arbitrary blue sky numbers the whole thing is a LOT more enjoyable. On the other hand, if you intend to use the car for competition then of course you need a thought out plan with realistic goals.

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I started with a 70 sports roof with c4 and 2bbl 302. I currently has a T5, 8 inch rear (3.89), and a 351w roller block that is about 430hp/430tq (thread is below on engine build). I have lowering engine mounts and a drop base air cleaner, but have proper clearance for my rpm air gap intake manifold. FWIW, I have been driving it this way for years and the T5 and 8 inch rear end have not exploded. I would do it again. Plenty of power now and room for more if i want to make it a stroker later on. 

 

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sub 11 could be done with both motor combos.

roll cage not needed but a 5 point bar minimum. I would suggest swing out on the drivers side..

ran a pump gas 393 and it put print out 11.15 slips all day..

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