Big block engine mounting.

[ChevyRacefan]

Hello, Everyone.
My truck is a factory small block truck.
I plan down the road to put a big block in it.
I have n.o.s. g.m. big block frame stands original for 396-402 big block truck 69?-72, and the puck type rubber mounts that bolt to the engine.
I also have frame stands from the big block donor truck, that was a early to mid 80's square body dually , and iirc use the newer clam shell mount and engine bracket.
Has anyone used 80's square body big block frame stands and mounts in 67-72 trucks to use the clam shell type mounts? I know the 73-87 engine cross member and front end is swapped in these 67-72 for disc brakes.
Or can you mount the later clam shell on the 67-72 frame stands.
Thank You for any help.

[Ironangel]

I used the pre-72 BB stands with the standard 3 hole (7/16-14 hole in the center) SB motor mounts like these. Use grade-8 7/16-14 bolts with over sized washers...That accomplished a couple of things...It puts the MK4 block in the same position as the Small Block and allows for some adjustment on the stands. I was pleasantly surprised that when I used that set up the SB fan shroud worked, and the 350THM bolted right back up to the cross member and drive shaft length was still good... https://www.cjponyparts.com/motor-mo...1972/p/MM2282/