Originally Posted by 1971BB427
Do you mean BBC frame monuts, or motor mounts? The motor mounts on a SBC and BBC siit in the same position, but BBC motor mounts are taller than SBC motor mounts. The frame mounts are different, but not sure in what way.
I could never run tall valve covers on the 427 in my Camaro, as they just wouldn't clear the heater outlets, and the brake booster. I even ran SBC motor mounts to drop it down, and still not enough clearance.
Have a look in my journal ... entries #9 to #12 on page 13.
I tried to label all of the mounts with bits of masking tape in order to record and share what I had to learn in what I felt was "the hard way", but I'm looking at all of this again, and second-guessing myself ... could I have possibly mis-labeled those mounts and brackets?
You see, I had 2 different "donor" trucks that I was scavenging parts from. One was of course the 79 C20 Camper Special, and the other one was a bit of a mystery ... what I believe was a 1976 C10 with a 350?
The C10 had a much shorter (vertically) frame rails than the C20 ... much closer to the frame rail height of my 910. It made sense to me that the frame brackets from this C10 would be the best option.
However, when I set what I believed to be the C20/454 brackets in place, they were much closer to being the correct length.
I did have to grind a wee bit (1/4") of material off the inside of the frame rail and drill new bolt holes. I had made some rough measurements between the cross-bolt mounting holes of the assembled mounts, and it was bang on!
The trans c/member also came from the 76 C10, and was also pretty much a "bolt-in" other than drilling a couple of holes.