My dad has 78 that he is probably going to part out and he was going to let me have the front disk brake setup for my 69 Chevelle. I have been looking and searching for info about size of the rotors but either not having luck or there isn't anything here about them. I figure that the stock rotors are 11" but not sure. I wanted to go with the 12" conversion but the I am not sure if the spindal will support a 12". Does anyone know if this will work or should I just leave it with the stock rotors and be glad I don't have drums up front.

Thanks

I believe the 78-86 G bodies use tyhe weak azz 10" brakes. i wouldn't bother. You are better off with drums than 10" brakes.

Ok, I was totally wrong on the year it is a 77. Does that make a difference?

Yep, 77 uses 11" brakes and also utilizes the old school "tall" spindles. Do a search for tall spindle conversion both here and at team chevelle. it has been discussed at length many times.