This is a good indication that your timing is too far retarded.
Has any one had any luck keeping paint on their 460 heads?. A few trys and the paint keeps burning off of the stock exhaust runners, (log exhaust)
This is a good indication that your timing is too far retarded.
Are you painting the heads themselves or the exhaust logs? Are you using engine enamel?
Timing seems to be good and to doble check had it tuned by the pro. Same situation on a friend's boat, another 460 with different mfg. logs.
Paint on the heads, not the logs. I've used engine paint and then also have tried rustoleum w/primer. Cleaned what I thought was pretty good before the paint.