[Formulajones]

These old chamber heads seem to like timing on some engines. My buddy would occasionally take his 69 COPO 427 camaro to the race track for fun back in the 80's and early 90's, and that thing always ran best with 42 degrees of timing in it.

I used to run the Nomad here back in that time frame with it's 327, with hump heads, and I always kept the timing at 41 on that thing where it ran best, and daily drove it that way.

My 454 Chevelle, even with more modern AFR heads with heart shaped chambers makes best power at 38 degrees, which I didn't expect at all.

Then take dad's 571 Pontiac for instance, with it's old style Edelbrock bathtub style chamber heads that everyone says likes more timing, didn't like anything more than 34 degrees when that was on the dyno.

Go figure. That's why I prefer to dyno and test these things, they seem to be all over the place for what they like on timing. No set number.