'72 4WD Vortec swap - motor mounts??

[hogpuke]

I'm installing a 5.3L Vortec into a '72 Chev. 4WD and wanted to know if any of you who've done this before have had to modify the stock crossmember for the motor mounts. I thought the adaptor plates were supposed to locate the original three-bolt motor mount in the stock location, but they don't. And it looks like they couldn't anyway - the bottom hole in the three-hole mount is 16" from the bell housing mating surface on the small block and on the 5.3L there's just too much stuff in the way at 16". The adaptor locates that hole at 14 1/4". That could be an easy fix by sliding the mount back and drilling new holes except that besides that, it looks like the oil pan and some of the block castings are too wide to fit into the crossmember. Anyhow, the engine's in and bolted to the trans bell housing and resting on a bottle jack until I can get the crossmember figured out. Any help would sure be appreciated. Thanks!