A body disc spindles on a B body?

motorhead446 said
Can anyone tell me if A body disc spindles (73-76) can be used on a 66B body?

Yes since they are the same dimensionally as the B Body spindles. I put a set on a 69 Charger I once owned - bolted right on and stopped the car much better than the 10 inch drums that were on it.

motorhead446 said
anything to change? Thinking of putting front discs on my 66 Net. I have a complete A body disc set up to use.

Nope - bolts right on using your B Body upper and lower ball joints.