K5 Body Mounts

[Critter]

I got all of the bolts and old body mounts removed. Unfortunately the PO had welded all of the bolts to the floorboard. Thanks to a lot of help from JTRUX and his grinder, we got everything removed. Anyway, to make a long story short, I don’t believe any or my bolts are original. I would really like for someone to help me out with the diameter and lengths of these bolts. The ones that were there are too big to go back into the new washers that came with my Energy Suspension kit. Also, the diagrams that I have seen show that all of the original bolts should be carriage bolts, except the one right under your feet in the floorboard. Is grade 8 entirely necessary? Has anybody had trouble with using a grade 5 under normal conditions? I have a feeling my floorboards would crack before I broke a bolt. I appreciate any more info.

[Critter]

OK, I feel dumb. After doing a little research, it looks like the factory welded the bolts to the floor pan. At any rate, I still need some new ones. What doesn’t make sense is that the Energy suspension kit won’t allow me to use the same bolts. If they are indeed the original ones, they are too big for my new kit! Any ideas???

[70gmcjimmy]

Wish I could help, Critter, I am using the LMC rubber set and I compared a couple of the bolts and they seem the same. Havent opened all yet as each position is individually packaged. The foot area bolts in mine look like grade 5(3 lines on the head) so I wonder if your stuff was changed before and welded back in like factory. That's 1/2" bolts so grade 5 should sure be enuff, especially when you consider that they get torqued 40-55# according to the assembly manual.

Later---DAC

[1972 Banana]

Critter,

Sorry I never got you the bolt info! I ended up ordering mine from LMC it cost me about $40.00,the floor board bolts that were in mine were to big for my washers that came with the kit. the local Ace Harware store had some fender washers that worked just fine.If you still need the info I will try to find the piece of paper at work with the dimensions. My local bolt supplier could only sell them to me 25 at a time!

[Critter]

the floor board bolts that were in mine were to big for my washers that came with the kit.

That was my problem. I ended up drilling out the washers for the radiator support and the main floorpan. The bolt in the floorpan was between a 1/2 and a 5/8 so...maybe it was a 9/16. Either way, I put a 1/2 in it for now. Maybe I will change it if I can find the right bolt someday.

[5150]

1972 Banana-Anymore info on the length of the bolts?

[1972 Banana]

The bolts I had to replace were as follows

3/8 by 4 1/2 inch two of them
3/8 by 10 inch two of them
3/8 by 5 1/2 inch four of them

the other bolts I was able to salvage but the floor pan bolts were to big for the washers in the kit so I was able to get a fender washer from the hardware stor and it worked ok.

[5150]

How many bolts in all? 14?

[Critter]

By my count, I remember 12:

Under radiator support x 2 (7/16 I think)
Main cab support in floor pan x 2 (slightly larger than 1/2" maybe 9/16ths?)
"Bed area" x 8 (see 1972Banana's list above)

Sorry for not remembering the lengths. I had to make a couple of trips to the hardware store to get things right. Obviously, too short is a problem, but you can easily go too long as there are often brackets and things directly below the mount areas. I suggest pulling one out from each side and taking them to be matched up. Also, I called Summit and asked about the bolts, they confirmed with Energy Suspension that ALL of the bolts are specialty bolts and no hardware store will have exact matches for them. In my opinion, try to reuse the large bolt in the floor pan area, it seams the have very odd dimensions and tapers. Otherwise, the rest of them cross over with regular hardware just fine. Hope this helps.

[1972 Banana]

12 bolts total,8 are 3/8th. The hardware store bolts I found were grade three's and are not strong enough,I ended up getting them from LMC.