66 Frame w/ 1987 Disc brake Cross Member question
 

Just putting the final touches on swapping in a 1987 Disc Brake front end under my 1966. I was surprized with how simple it was to do.

I got the motor mount frame brackets from the 1987 and I discovered the brackets are too tall for the 1966 frame. Apparently the 1987 frame is 3/4" taller. For you guys who did this conversion, did you use the new brackets with 3/4" spacers or did you reuse the original 1966 brackets? If I had spacers made, would that affect the installation height of the engine?

Thank you,
Kevin C

Re: 66 Frame w/ 1987 Disc brake Cross Member question
 

We used the later model motor mounts, had to slightly dish out the frame top lip.....and redrilled the crossmember to allow the mount to move down......it worked great.....will try to get you some pictures..

http://kieth.smugmug.com/Trucks/66-G...9244&k=NP2nXZh

after you go to the above photo just click thru the thumbnails and you can see how we did it. Kieth 66 :gmc2:

Re: 66 Frame w/ 1987 Disc brake Cross Member question
 

I did the opposite added 1/2 spacer on top of frame, it's been 20 years, seems fine.

Re: 66 Frame w/ 1987 Disc brake Cross Member question
 

if you can source a 2wd 3/4 ton set they are a direct boltin, since the 3/4 frame is not as tall as the 1/2

Re: 66 Frame w/ 1987 Disc brake Cross Member question
 

This

Or you can shorten the C10 motor mount brackets.....or just add the spacer to the top of the frame. Either way you will want the bottom of the bracket on the crossmember. You will also have to trim back the top flange of the frame, for the later model motor mount brackets. If you still have the '87 frame you can use that as a reference.

Re: 66 Frame w/ 1987 Disc brake Cross Member question
 

Why not just use the original mounts? Worked for me...

Re: 66 Frame w/ 1987 Disc brake Cross Member question
 

I wanted to use the later model motor mounts because of the large size of the bracket and the rubber isolation material. I also wanted to keep the engine as low as possible and just a little forward so it did not touch the firewall. Kieth :gmc2:

Re: 66 Frame w/ 1987 Disc brake Cross Member question
 

The original style motor mounts can pull apart and let the engine move around. The '73 and up 'clamshell' motor mounts will not pull apart and let the engine move around.

Re: 66 Frame w/ 1987 Disc brake Cross Member question
 

Looks like either way I go with this, I need to notch the top part of the frame. Redrilling the crossmember so the top of the bracket sits flush to the top of the frame effectively moves the motor mounts closer together. Didn't that cause any issues when the motor went in?