A couple of things to try on your fuel boil issue.
The air cleaner you are using is a huge heat sink, try an open-style one for a week or so and see if it helps.
Thermoquad should help, if you have a good rebuildable one.
If not look at the phenolic body street demons, I put a 625 on my old truck and it took care of 95% of the heat issues I was having.
