How about this for the Franken motor thread
Ej257 bottom end( shortblock)
& the heads from a 25d motor?
I've been running this build for 14k now & short of being boosted this is a really nice improvement over a stock motor.
I've tried 87 oct , no knock. With 89 & 93 u actually see an improvement in throttle response & lower end power.
When I did the math w/ an online compression calculator, it came out to like 12.48:1
Hope this is useful info...
S.O.N