Tuning Dells

[chigger]

Detonation is usually caused by to much advance. Total advance should be around 28 deg. My problem is that the stock distributer clamp keeps slipping. Just recently I took measurements and made one out of billet aluminum. It looks just like the empi or bugpack. It won't work. The stock case stud doesn't stick up enough. The clamp is going to have to be reengineered before I am happy with it.
Slap a vacuum gauge on the motor or spray around the gaskets and throttle plate holes with carb cleaner and see if the idle changes. Well used carbs usually have leaks at the throttle shafts. All four throats should pull the same vacuum and be smooth as the rpms go up.
45 dells are really big for your engine. You might try using the recomended venturies and jets for the 40 sized carb. Hope some of this helps.
Check you valve clearance too and maybe a compression test. You might have a burned or sticking valve.