Been running Autolite 25's gapped at .035 with my old points distributor but made the swap to a GM HEI distributor this morning. Do I run hotter plugs or just gap these 25's to .045? Any suggestions are welcome.

Also, do I set initial timing where the old points distributor seemed to like it? Was about 16 degrees initial.

Thank You,

Timing should stay the same,,the distributor is just a trigger,I'd try the larger plug gap unless you're using nitrous or running high compression,and I run 1 or 2 ranges colder,in performance applications than what the book calls for stock.

I use .040".

What advance curve does the new distributor have, and how does it compare to the old one?

With a good coil I like .045 but I don't gap any larger even with the Jacobs coil.

I use .060 with a better coil but you must get a very good set op plug wires or it will fire everything except the plug.

I've got 10.25:1 compression. I'm not sure what the curve is exactly or how to really figure that out unless it is the initial + mechanical + vaccum? I know it's got a 10 degree vac can on it but will need to check the mechanical. The old points dist. was 16 initial + 20 mechanical and would all come in around 2500 rpm. With vaccum it was 52.
Is it better to run a somewhat colder plug like Rapid Robert does and what does it benefit?

Stick with the plug that you were running if it was working out okay for you. Bump up the gap to .045".

Mike