Engine Mount Bracket or Whatever It's Called Differences

[Dads79GMC]

OK, so I have two sets of these. One set is from my original 1979 LWB frame (dirty ones), and the other set is from a SWB frame (cleaner ones). The cleaner ones are shorter? Why? The longer ones reach the top of the frame, and the cleaner ones line-up under the top lip of the frame. Again, why would these be different, and which ones should I use?

[jetmech85]

I wonder if a heavy half frame is just a little beefier than a SWB frame making it necessary for a longer motor mount support? Or if the shorter one is from an '81 or newer maybe the frame is different in that area as part of the weight savings for that body style.

[Dads79GMC]

Both the LWB and SWB are Heavy Half frames, I should have mentioned that earlier.
LWB is a 79, the SWB I think is also a 79.

[KrazyRay]

Did one set come from a big block truck? The big blocks are different.

[Dads79GMC]

Originally Posted by KrazyRay

Did one set come from a big block truck? The big blocks are different.

I can partially answer that question: Fact - the larger set is from the original LWB frame, with the original 350, no big block. As for the smaller set, I don't know.

I think I'll go with the original longer ones rather than the set that came with the donor SWB frame.

Thanks for the input. Mike