The bore is 3.9" (99.1 mm) and the stroke is 3.62" (91.9 mm)

 

Bet those things like to spin!!
I see alot of vette guys and most LS1 guys really making tons of power with the 347, Always was curious as to why they never went for more cubes on some of those fully built motors they make, they always seem to stick with the 347 cubes. Any particular reason Kyle?

 

x2......

 

My 346/347 runs pretty good. Probably run better with a 370 though. Just a thought.

I built the small motor at the time because it was more economical for me. In other words.............I'm broke! I'm in the gotta do more with less camp.

 

Aluminum block
great aftermarket
good power and decent economy.

If I ever am forced to upgrade, the 347 is what I will do for the above reasons, plus it'd fit my blower nicely

 

The fact that it's aluminum is the only benefit I see in a 347.
Aftermarket for a 370 is the same as for a LS1 and fuel economy is negligible when those vette guys are shooting at 1000rwhp. I'm curious as to why the vette guys stick with that displacement when they are rebuilding an engine for more boost or upgrades or whatever. I would think since it's outta the car and disassembled that they would up the cubes. Only thing I can think of is the bore x stoke gives it some added advantages over a 6L +. But I don't know, that's why I'm asking.

 

370 bro

 

370 is still a good size for a street 76mm, but if heads and everything else is the same on kill the 346 will usually make more avg power in the 4-65k range. All you need is enough CI for your turbo, or Sc to work efficiently. Too many CI's for a given compressor, or turbine and power will drop. The people that think more CI's are allways better have never class raced.

 

what do u mean

 

One of the major reasons someone would stay with a 347 even when building their aluminum block is that outside of stroking the hell out of one or re-sleeving the block, due to only being able to bore one out 0.010” to 0.020” depending on the year of the block, they are limited in what they can do. At least when someone throws a 4” stroke crank in a 6.0, you still end up with at least a square motor. Whereas stroking a 5.7 to a 383, you end up with a well under-square motor with a 3.905” bore x 4.00” stroke or a 384 if you went with a 3.910” bore. Then to top it off, you’re limited on valve size with the relatively small bore sizes. I feel that most folks would just rather keep their money in their pockets and keep a happy good revving motor or take the plunge and move up to another block entirely.