I have my motor out for some winter upgrades and it looks like I am getting some reversion? I installed my cam 2 degrees advanced but would like to retard it as I am not running 11:1 compression and would like a little more rpm on the top end. I have Imco powerflow exhaust and have been told these are not the best for reversion. Attached is my cam card and some exhaust pics. Would retarding it back to straight up or even a degree or two retarded make that much difference? Engine in a 548 10:1 BBC with 088 heads.