No elongation of holes that I know of; the '74 should bolt right in. My donor truck was a '75. Check my website; I chronicled the swap.

Dunno about the C20, but a '87 C10 would swap. The nuts and bolts are all metric from '85 to '87, though......


Mike from Alabama
My truck on Stovebolt
My website
Why do we drive on a parkway, and park on a driveway?