Any one have a chart or know what the best advance setting for 2200 to 2500 rpm range?I seem to not have much power after 2800 when pulling trailer about 19,000 lbs total truck and trailer.30 lbs boost and 1200 and I have to back out of the throttle to control temp. I think I am at 15 to 15.5 now. Homemade 100 plate 3 1/2 exh cold air filter boost fooler the rest stock

 

16.5 to 17 degrees is about all a stock HG can take in the safe range. If you have studs or an o-ringed head, I like 19* for towing.