308 or 347
 

The motor I got has, .030 over which im getting. 040, but the pistons cost me about 500 and a 347 kit cost me 1100. Which I would rather get the 347 kit but I have read alot about having the right set up, like the heads, cam, and intake. I can't afford to buy all of that so im going to have to settle with what I got.
Edelbrock performance heads
X303 cam
Trick flow r series intake
Supercharged 8-10 lbs of boost
Tko 5 speed
Would like to now if this set up would work on a 347 or should I just stay with 308 and can u'll explain why, just would like to have some info.

Well the 347 with boost puts you in the blocks hp limit! Everything else 347 hands down, its always a H/C/I choice with any cuin!

Regardless if someone says otherwise and they will, use common sense, it made good power as a 306 right? add 40cuin and itll be that much stronger! Is it the best combo for a 347 NO, but if it is all that money allows then it`ll do!

Those heads and cam in a 347 are going to make peak power at like 5,000-5,500rpm. The blower will let you make power to the blocks limits, so if you're going to use those parts it really comes down to what gears you have and how you want to use it, since cid with the same parts will mostly change rpm where peak power occurs. 302 if you wanna turn to 6k+, 347 if you wanna stay at max 5,500.

Depends on usage too, road racing and autox you generally want a shorter stroke for longevity, assuming the same rpm. 6k rpm in a 347 is a lot more stress on the block than a 302, and you need more money for reliability with a longer stroke.

Only reason I went 308 was because I got the whole rotating assembly(see sig) for $900.....if you know anything about the parts I have listed....theres well over a couple thousand If I would have bought them new. I couldnt pass the deal up,and to be honest i love my car the way it is.

67mustang302 I just want to make sure I understand what ur saying. If I go with the 347 I should go with a higher gears and if I go with the 308 I should go low gears. Well please correct me if im wrong. I have 3:55 gears now on the car how will those work out

I would say not worth a damn at the track with either engine. For the street, they would be fine.

Mine work great for me!!!

The more rpm you can turn the lower(numerically higher) gear ratio you can(should) run. A 4.56 gear in a car that only turns 5k rpm or a 3.00 gear in a car that turns 7k rpm are both mis-matches.

3.55 is a decent middle of the road gear in most cases, it'd work ok in either case but better for a 302 or 331. A 347 with the parts you have, and the 3.55 gear is probably about the most you want to run unless you don't mind shifting like mad.

The reality is those parts aren't any good for a 347, a 347 needs quite a bit more head and cam than a 302.

Gearing is also dictated by usage....road racing and drag racing require different gear ratio selection.

Holycrap someone gets it!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!