85 head with 86 piston results

starsnbars · Post by **starsnbars** » Wed Aug 27, 2008 3:47 pm

I was running a stock 85 spree, after rebuild I am now using an 86 crank and piston but kept my 85 head on. Before rebuild, I was lucky to hit 28, now I'm hitting 33 easy on straightaways and about 36mph on downhills. This was in the perf tech docs, and after trying it, I would definitely recommend doing this for some top-end gain.

Diesel Spree · Post by **Diesel Spree** » Wed Aug 27, 2008 3:55 pm

i dont no but i think it might just be rebuilding it is what gave u the speed but thats cool it worked for u

chevyguyjay · Post by **chevyguyjay** » Wed Aug 27, 2008 6:33 pm

if what u say is true that u have a 85 motor, an 86 crank will not fit in a 85 block. the crank is bigger. u can put a 85 crank in a 86 block.

starsnbars · Post by **starsnbars** » Wed Aug 27, 2008 9:03 pm

86 crankcase