I have a 1935 Chevy with a 350 engine. The transmission went out so I'm replacing it. Pulled the grill and radiator to pull the engine and transmission together. The existing motor mounts did not fail but left a lot to be desired. Holes were egged. I designed foam mounts, here's a lineup shot. Glued and test fit. Joints waxed and coated with sheetrock mud. In the bucket, getting filled with sand. Cleaned up, drilled, and ready to go. I didn't account for shrinkage, and there was practically none on the height. If it cools from the bottom up and continues to take metal maybe it doens't shrink much. Re marked the ends of the cylinders for engine bolts and drilled hole from center punch front to center punch back. Used a lineup pin And aligned it with the drill bit then sat the center punch on the pin. The mounting bolts are pretty parallel even though the cylinders aren't.