I had a Holley model 4165 650 cfm spread bore on both my '63 C10 and '77 Blazer. No trouble with either of them.
I currently have a Holley model 4175 650 cfm on my '62 C10 and the only trouble I had with it was flooding from the rear vent tube on hard deceleration. I built a connector tube out of solid fuel line and connected the front and rear vents, then drilled a couple of vent holes in the top of the connector and that solved the problem.
I've been using Holley carbs since the late 70's with no major issues.
