[padresag]

there are 8 body mount positions. 1 insulator mounts top of the frame and the other on the lower side. those rubber tabs unite inside of the frame hole. the part nbrs superseeded. doesn't mean that they are the same but can be used, one can always trim them down if you desire 1 3/4" instead of 2". someone did say the hole was larger in the new one. you can always bush them. these insulators were used up into about 2002 blazers I believe,
Lewis is an old gm partsman whose dad had a GMC dealership in the day. he has all of the old parts books for these truck. he shows up from time to time on Jollies old GMC site. he is the one that gave me the parts nbrs. wonderful old gentleman.
I have seen kits for the 69-72 suburban that the insulators were round instead of rectangular and I think that they are available from some of these reproduction retailers
here is the original quote again. the flat part of it is under 3/4", not by much and the raised portion is about another 0.050" or so.
the following is what Lewis Matkin sent to me. the pictures are mine and
I will have some more later for you as I have to check something out

Ron, this is Lewis. Please forgive me for not getting back sooner, but I
have been busy in my work for the church I serve. I checked both my
65-66 parts manual and my 67-72 parts manual. This is what I discovered:
1964-6 body mounts are p/n 3794779, w/dimentions of 1.76" w; 3.00" l;
0.92" thick, needing 8 (up & lwr same). The 67-8 p/n is 3909351 up &
lwr, 69-72 uses 3909351 as the lwr, but p/n 3946246 is the upr. No
dimentions are given for these cushions, and it seems that the frame
changed in '69. Qty's in 67-8 are 16, with 69-72 requiring 10 of each.
If you have dimentional axcess to the later cushions, these 64-66
dimentions should help you. Like you, I suspect that the 67-8 cushions
will work, but there is no superseded p/n's between the body styles. I
can tell you that years ago I bought cab mounts for my 65 and the p/n's
had superseded to the mounts for the 67-72 cabs. I hope that this info
is of some assistance in answerring this question.

the dimensions sound right. the .92" high includes the raised section
around the bolt hole.
The measurement excl the raised section is between about .73-.74" high
hope that helps

Ithink that they wouldn't be to hard to make .the bonding of the rubber to the steel so that it stays together is the question. if on has access to a milling machine they could thickness them properly put the lip on and in business. i do have a hunk of rubber which appears to be the appropriate denseness and hardness for it. my brother got it about 25 years ago. he has been dead for 20 so I cannot ask him about it. it did come from C.P.Anderson Rubber, but the dips--t that I talked to there was no help in trying to get more from them, and of course when it is a small order; don't bother me. in other words it wasn't worth his time to check it out. they did about 10 years ago have a branch here in Victoria but it was closed down , now we know why. they didn't like dealing with individuals even if you were a business
ron