Hey guys..I have a buddy I am trying to help out..He recently swapped in a late model mid 90s truck motor (360 Magnum) into his coronet..Since the 360 engine was fuel injected he swapped the entire top end from his 72 318 onto the 360 shortblock...Can anyone tell me what kind of compression the motor will have now?...Are the 318 heads a step backwards over the 360 heads?
In 192 the 318 had an 8.6:1 compression ratio, which isn't so hot. Not sure what that 360 was running, though.
"Are the 318 heads a step backwards over the 360 heads?"Yes, you are choking the engine down with 318 heads. 360 heads have larger valves and flow better.
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Put the magnum heads back on and buy an aftermarket carb intake. Look on ebay they have intakes that will fit both LA and Magnum heads. And there cheap.
Like the posts before, get rid of the 318 heads, smaller valves, ports, chambers everything is smaller. The motor won't make much power over 4000 rpm with those heads. I agree with 785, put the mag. heads on. They are very good breathing heads.