(2)450 DP's vs (2)750 DP's

To be honest, I don’t have a place close by I can really run that type of test. No tracks close by and the closest doesn’t have a test and tune time that I’m able to attend at this point. Next time I make a wot run I’ll see if I can scout out a decent location to do it.
That will tell you if the chamber is happy or not at your current timing. If you have ngk plugs in it, you can make 2 degree swings starting at like 28deg and watch the mark move around the bend of the ground strap.