Motor mount tower?

[toms84ss]

Did a search and didn't find what I was looking for. I swapped a complete front end from an 87 1/2 ton Burb to my 65 1/2 ton. I used the X-member, control arms, brakes and all. I also want to use the later model motor mounts but hit a snag. Seems the motor mount towers on the Burb are about 3/4 too tall to line up with the top of the 65 frame. Me and my buddy did some measuring and found a tower that's the right length for this swap. But we only found one. What year trucks do I need to be looking for in the yards to find the shorter towers? ...