[Bonos]

Fuzzy,
When you do your carb adjustment make sure you have a vacumn gauge atteched so you will know when you have the hignest inches of vacumn
obtained.
Also check vacumn readings at 2700 -3000 rpm's to insure proper ajustment at higher rpm's.
The backfire you hear between shifts will come from fresh air being sucked into the exhaust system from loose bolts or blown gaskets at exhaust manifolds or collectors.

Bonos