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86 newbie 12-02-2011 11:37 PM

331 and 347 questions
ok i have a stock 302 block and wanna make a stroker. What is a 347? is it still the 302 block bored to max or is it another block. If its the same block then what makes it the 347 also whats the bore on it and a 331?

tinman 12-03-2011 12:19 AM

A 347 is a 302 bored .030 over and fitted with a 3.40" stroke crankshaft with the correct pistons and rods.
A 331 is also a 302 bored .030 over and using a 3.25 stroke crank with the correct rods and pistons.
You really can't bore a 302 block past about .060" and have any degree of safety as far is block life goes, even then not all 302 blocks can go that big......

86 newbie 12-03-2011 12:35 AM

ok thank you that helps a ton! is there a certain brand thats good for the 347 stroker kit?

86 newbie 12-03-2011 12:37 AM

also if you have to bore a 302 block out to a .40 over can u still use the 3.40' crankshaft and still be a 347?

Venomantidote95 12-03-2011 05:07 AM

U start spliting hairs then 348 349 lol you still basically have a 347...

Venomantidote95 12-03-2011 05:10 AM

You have 2 rods to choose from 5.4 or 5.315 that affects piston hiegth and choice.

AdderMk2 12-03-2011 06:07 AM

have someone build the engine for you.

86 newbie 12-03-2011 03:35 PM

thanks guys and adder i want to build it, thats why im asking,i asked because i wanna learn and so forth

tinman 12-03-2011 11:52 PM

There's a lot of good places to buy the kits from.
One bit of info however, someplaces will tell you it's a balanced kit or they will balance it for $75 or something.
Thats B.S. unless they have the harmonic balncer and the flexplate/flywheel that you're going to be using.
I would aviod the big mail order places like Summit and Jeg's simply because there prices are higher than than some of the smaller places.
I've done a couple engines and I got the rotating assembly from Coast High Performance in California. They have good service and fast shipping. They are part of a company that makes forged pistons so if you want a specail relief or anything like that they are good with it......

Venomantidote95 12-04-2011 08:57 PM

There are people here that can help u just ask if everyone paid someone else many of us wouldnt be here on the forums or have the cars we have.... Good luck! As stated dont get the kit prebalanced for many reasons.

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