yorkie

This is a 383 stroker motor with -12cc pistons for a CR of about 10.8:1 and it has bad detonation (mainly on the 1-2 shift, just as is goes into 2nd gear, then crack the throttle slightly and it pings/ detonates.) I have had 4 computer's for pcmforless, (the last one he left fueling 383 and went with stock timing tables) It made no difference, I feel timing is not the factor now, I think it is running to lean. Going down the road it is fine, or once in 3rd you can put a load on it and no pinging. Any suggestions on what to try next, has new fuel filter and I checked fuel at WOT Like 44... At idle with vac tube off it is 47 and tube on 38/9. Gutted the cat, removed the EGR system and removed air pump. I put a "penny" in each air tube and screwed the 3/4X 20 pipe back in got back to the house and the penny had melted on the drivers side the other side was OK.

Eric