Motor mount tower?

[toms84ss]

Did a search and didn't find what I was looking for. I swapped a complete front end from an 87 1/2 ton Burb to my 65 1/2 ton. I used the X-member, control arms, brakes and all. I also want to use the later model motor mounts but hit a snag. Seems the motor mount towers on the Burb are about 3/4 too tall to line up with the top of the 65 frame. Me and my buddy did some measuring and found a tower that's the right length for this swap. But we only found one. What year trucks do I need to be looking for in the yards to find the shorter towers? ...

[Captainfab]

I was thinking that they changed in about '81 when they changed the frame and the body slightly. I would have thought the '87 would have the shorter ones. You might try looking at an early 80's one if you can find one. You just need to measure the height on the frame to know if it will work.

[toms84ss]

Went to the bone yard today. It looks like the 3/4 ton trucks and Burbs have the shorter tower then the 1/2 tons. Year of vehicle doesn't seem to matter. Can any one confirm this? I didn't get a chance to measure anything. Just took a quick look on the way home after work.

[Chevy Fleetside]

you have to trim the frame back about 3/4" for them so sit down on the frame.

[toms84ss]

Originally Posted by Chevy Fleetside

you have to trim the frame back about 3/4" for them so sit down on the frame.

Not sure what you mean by this. If i line up the bottom holes in the cross member with the towers, they sit about 3/4 of an inch above the top of the frame. Not sure what would be trimmed to get them to fit. Got any pictures of what you mean?

[joe231]

you can cut and weld the towers to make then shorter

[Chevy Fleetside]

Something like this. I used aftermarket and still had to trim the frame back. If you look close you can see where I cut the frame back. It is kinda nerve racking to do. I looked at it for days before I even made a cut. A friend of mine used perches and mounts out of a 74 truck and he trimmed the frame back and drilled new holes in the crossmember for the bottom of the perches.

[joe231]

very good idea!!!

[Captainfab]

Originally Posted by toms84ss

Went to the bone yard today. It looks like the 3/4 ton trucks and Burbs have the shorter tower then the 1/2 tons. Year of vehicle doesn't seem to matter. Can any one confirm this? I didn't get a chance to measure anything. Just took a quick look on the way home after work.

I believe you're correct on the differences being 1/2 ton versus 3/4 ton brackets. I did some measuring at the shop today and the 1/2 ton frames I measured were 6" tall where the motor mount bracket goes, and the 3/4 ton frames were 5 5/8". These were in the '74-'79 range. I can't believe I hadn't figured this out.....I had always thought it was the '81 and newer ones. Thanks for pointing this out

Regarding the frame trimming. That will need to be done to get the motor mount brackets to sit correctly. It's just the top flange that needs to be trimmed. You can look at and measure a '73-'87 frame to get the idea and dimensions. That's how I do it. This is even more important when converting to a big block with headers.