Engine mounts further forward? 73-87 front swap related

[J1MMY]

I've got to the point where the truck is completely torn-down and the '79 front crossmember is bolted up with a view to dropping the 292 and 5 speed in, so I can make sure everything is lined up before blasting and painting the frame.

I've run into a few issues and have a few questions - they're not likely to be anything that hasn't been picked up before but typically all my bookmarks were kept on my old (dead) computer and I can't find them again so, in no particular order here is what is holding me up:

1. I am unable to source any C20/30 engine mount towers (? I think you call them, the brackets that bolt to the top of the frame and the crossmember) so I am having to use the C10 ones. However, I recall reading that using these moves the engine away from the stock mounting point? If so, by how much and can that be negated by the slotted mounting holes on the crossmember and the mount towers? This info will help me to avoid cutting any more metal from the top of the frame than is necessary.





2. I ordered a Davidson Performance 292 engine mount adapted through 12bolt Tom which arrived last week (beautiful looking piece of metalwork) which I have bolted to the engine, so now the 292 can mount up in the 250's mounting points.The original mounts and brackets are now obsolete. Sadly I don't have the '79 I6 motor mount brackets. what is now the best type of motor mount brackets to use?



Finally, is this gap between the outside of the frame and the sides of the crossmember consistent with a '73-'87 swap?





Thanks