[purple1967camaro]

hi everyone. i just put a new top end on my 350 motor. i went from 76cc heads to 64cc. and from 1.5 rockers to 1.6 rockers. and i cant seem to get the timing right. before i did the build up i always had my car set at 10 degrees advanced with the timing advance canister plugged in and it always ran perfect. but now with the new heads on it doesnt seem to run or idle right at 10 and i dont know where to go next. please post any suggestions because i have tried everything i know! thanks!!

[DoubleVision]

have you checked it for vacuum leaks? Are the valves in proper adjustment?

[Frisco]

With the higher compression you more than likely need to increase your initial advance. Bump it up some and also check the 'Total Mechanical' timing. If the Total mechanical is greater than 38 degrees at 2500-3000 RPM you will need to adjust that so that you do not exceed 38 degrees.

A simple road check is to drive the car in high gear at around 35 MPH up a slight incline. If there is any pinging drop the timing down 2 degrees and road test again and re-adjust the timing until there is no pinging.

Be sure to set the timing with the vacuum advance dis-connected and plugged! Re-connect it after you have set the timing.