Thread: 307 stoke?

Tweet

I know I will be raked over the coals for this one!!!

Could you increase the stroke on a 307 using a 305 or even 350 crank, and would that even be streetable?

Originally Posted by gte436e

I know I will be raked over the coals for this one!!!

Could you increase the stroke on a 307 using a 305 or even 350 crank, and would that even be streetable?

I've read of some fellows doing this with 400 rods, 350/305 crank, 307 pistons for a stack of 8.980". I'm not sure how the piston skirts/crank counterweights would like it. You would have to balance the whole mess and that alone would make it less cost efficient than starting with a 350 short block in the first place in my opinion. Well, that, and the fact that you end up with a 328 instead of a 350.

AND.....you end up with the pistons down in the hole by 0.045" or so....I have heard that the stack up that Tech describes adds up to
8.980 or 8.960....either way makes for a thick head gasket equivalent (-0.045 deck plus real gasket thickness of 0.020 or so equals 0.065")

Also, the 3.875 bore means you have to run essentially 283 friendly valve sizes....not conductive to performance.

If you have a bunch of parts laying around, need to assembly a junk motor out of them, and dont care if it has any performance, yes, it would be streetable. If you have to buy parts, it is a waste of money.

307 TECH TIP from Fat Hack over on HAMB...joe