1972 C20 Big Block Engine Mounts

[traymond73]

New to the board. Basic info before I pose my question:

1972 C20 Super Cheyenne with stock 402 and TH400
Swapping out engine for a 500 HP 468 and 3000 RPM torque converter
The truck appears to have the correct 1972 big block engine brackets.

My questions:
1. Do I need to replace both the engine mounts and the brackets? Or will just swapping out the mounts be enough?

2. My understanding is that the 1972s used a different mounting set-up than previous years. What is that set-up? pictures?

3. After seeing number 2 above, can someone point me to where the correct mounts for 1972 big blocks are actually sold?

Thanks in advance!

[Ironangel]

Welcome to the Board! Heres a link to Classic Truck Parts, http://www.classicparts.com/Motor-Mounts/products/310/
And heres "Manes Truck Parts" http://www.manestruckparts.com/store...Category_ID=16
The 72 mounts and stands are unique to the 72's and very pricey! I used the pre 72 stands with the common small block Chevy motor mounts, works great and is much more reasonable in price as well.~Ghostrider~

[traymond73]

THanks for the response. If I go with the pre-1972 brackets/mounts, then I have a couple of questions:

1. Will this change where the engine sits? If so, what problems will this cause, if any?
2. Will the small block set-up be adequate for the 500 HP?

Thanks

Originally Posted by Ironangel

Welcome to the Board! Heres a link to Classic Truck Parts, http://www.classicparts.com/Motor-Mounts/products/310/
And heres "Manes Truck Parts" http://www.manestruckparts.com/store...Category_ID=16
The 72 mounts and stands are unique to the 72's and very pricey! I used the pre 72 stands with the common small block Chevy motor mounts, works great and is much more reasonable in price as well.~Ghostrider~

[So.Cal.Super]

If you already have the big block motor mounts personally I would stick with them. I swapped out the rubber internals for polyurethane and bolted everything together with Grade 8 hardware.
The mounts you have are beefier but will bolt right up to the new big block.
If I remember right it took a little finesse and I had to install the bracket on the block the bracket on the frame and then I think the polyurethane was last as we bolted the clamshell together. Minus my helper up top taking a chip out of the firewall paint for not paying attention while I was under guiding the tranny in. It went well.
Don't forget to fill the converter first and I opted for an SFI approved flexplate just to be safe.
Good luck

[traymond73]

Thanks. I can't seem to find the polyurethane internals anywhere. can you point me to someone who sells them?

Originally Posted by So.Cal.Super

If you already have the big block motor mounts personally I would stick with them. I swapped out the rubber internals for polyurethane and bolted everything together with Grade 8 hardware.
The mounts you have are beefier but will bolt right up to the new big block.
If I remember right it took a little finesse and I had to install the bracket on the block the bracket on the frame and then I think the polyurethane was last as we bolted the clamshell together. Minus my helper up top taking a chip out of the firewall paint for not paying attention while I was under guiding the tranny in. It went well.
Don't forget to fill the converter first and I opted for an SFI approved flexplate just to be safe.
Good luck

[So.Cal.Super]

http://www.summitracing.com/parts/pt...make/chevrolet

This is not the exact set, I bought mine years ago and it didn't come with the trans mount and I believe mine was made by energy suspension.

I always have to search 2 or 3 times and use 72 c20 suburban or some different combo including 71 because most parts companies computers if you pick 72 c20 400 it uses a small block.

but if you see in the pic those mounts are specific with the raised humps and how they sit between the clam shells.