64 on a 68 Frame?

[SCOTI]

I've seen the threads asking about the interchange on 62-66 frames.

Earlier this week, I saw a 62/63 cab on a 71-72 frame @ the frame/alignment shop. Anyone here have any info on what it specifically takes? I'm looking to educate myself..... but if someone has some research or background info already done (links or personal experience), that speeds the learning curve.

Thanks.....
Scot

[padresag]

60-62 has torsion bars and a x-member frame and this probably why they made the change. you wouldn't find much change in the basic frame between a 64 and 71 except for changes in the crossmembers. most components are interchangable. biggest crossmember change is in the trans area.
why would you want to change?
ron

[Captainfab]

There are only slight differences between the '67-'72 frames and the '63-'66 frames. The main differences being the front frame horns, the crossmember forward of the front suspension, and dimension differences in the rear cab mount location. Now as compared to the '60-'62 frames, in addition to what padresag already posted, the front cab mounts are wider side to side at 52" as compared to 41" for the '63-'72's. Also the bed mounts on the '60-62's are wider than the '63-'72's.

I haven't switched a '60-'66 body onto a '67-'72 frame, but that would be my first choice if I was looking for a different/better frame.

[SCOTI]

Why?
Would a 67-72 frame be a first choice if you had one @ your disposal & not being used vs. buying something different?

Because I have a 65 frame that's still .500" off from being square after coming home from the frame/alignment shop (I was going to use it for the start of a rolling chassis). I also have a 68 frame that isn't being used, is square, & already has the same mods I intended to do to the 65 frame done (It was free so I used it for practice ).

I'm going to measure differences today. My hunch is they're definitely close enough. I know from the bed back they are except for holes in the frame for incidentals (bumper brackets). I was curious if anyone here had actually done the swap & could detail their experience.

If they're close enough, I'll take measurements on the cab mounts to transfer them over @ the correct height/position. Then I'll cut the frame horns off the 65 frame & transplant.

[padresag]

well if you have both of them there it is easy to see the differences but I doubt that you will have any problems
ron

[SCOTI]

Originally Posted by padresag

well if you have both of them there it is easy to see the differences but I doubt that you will have any problems
ron

I'll report back in a bit once I get them both in the same location.

[protrash64]

Was there any sign of what happened to the 65 frame that you could tell?

[Captainfab]

Originally Posted by SCOTI

Why?
Would a 67-72 frame be a first choice if you had one @ your disposal & not being used vs. buying something different?

I may not have worded that quite correctly. What I meant was that if I needed a frame for a '60-'66 and I had a choice between a '67-'72 and a '73-'87 frame, the '67-'72 would be my first choice. Of course the best choice IMO would be a '63-'66 frame.

In your situation where you have a '68 frame, that would be an easy swap to accomodate your '64 body since the basic frames are identical. Just minor differences as I posted earlier

[SCOTI]

Originally Posted by protrash64

Was there any sign of what happened to the 65 frame that you could tell?

No, it was purchased bare. It was 7/8" off from the front bed panel rearward. We measured the front & it was good; we were pressed for time, the frame 'looked' straight so we loaded & left. After tweaking @ the frame shop it's .500" off. Some say it's not a big deal but I'm one of those guys that it must be square (I consider 1/16" or less to be square).

The 68lwb frame was picked up @ the same time the 65swb frame was (they were scrapping it). I wanted to try some ideas out & figured a free frame would be the ticket. The mods worked so I figured..... I've never done a lwb to swb chop & did that as well. After the mods, it's still within a 1/16".

As far as the comparison goes . . ...

As indicated, from the front bed panel back, the frames are very similar. The Panhard bar reinforcement plates are dimensionally larger on the 68's frame vs. the 65's. The frame mount is slightly different but similar in size.

The cab mounts are different w/the rears being just shy of 1" off the top of the 65's frame while the 68's are about ~1/8" off the top of the frame. The C/L's of the mounts vs. the trailing arm c.member & the standard trans c.member is about the same (I used those holes within both frames as reference points).

The front radiator core support areas are different. The 68 frame would need to have the holes for the mounts on the frame re-located/drilled. The height of the mounts are different as well w/the 65's being slightly above the frame rail (1/4") while the 68's were flush w/the frame rail. The overall height from the bottom of the frame rail to the top of the core support 'pad' was about the same on each so I'd have to see the bottom of a 64-66 core support to see what if any impact there might be (the obvious difference is how the bottom of the radiator is secured/located).

The frame horns are obviously different. The spacing from the C/L of the front c.member center bolt hole to the ends of the rails was very close but as we all know the shape was very different.

The swap is definitely do-able. The problem w/the truck I saw @ the frame repair shop (62/63 cab, short fleet bed, 71-72 swb frame) was the location of the mounts were ' off ' (dimensionally & height wise) causing alignment issues that required odd sized shims or hardware that was in a bind.

I ended the night just brainstorming..... I'm going to plan some type of jig that can attach to both frames & accurately locate the cab mounts vs. the front bed mounts & trailing arm c.member. With those locations set, the front core support mounts should be easy enough to determine. I'm going to look into it more this weekend. If my test jigs can be placed accurately (multiple times), I just might give it a try.

[aggie91]

Scot

Sound like this is a very doable swap. Seems the cab mounts would be the easiest to do, just cut the rivets off of each mount and swap them. A simple wooded jig would get them placed correctly off of the front mount.

The front horns/core support would be the more time comsuming job. You could even take this opportunity to move the bumper in closer to the body for a smoother fit...

Pictures would be nice....

[SCOTI]

Originally Posted by aggie91

The front horns/core support would be the more time comsuming job. You could even take this opportunity to move the bumper in closer to the body for a smoother fit...

[padresag]

I just put a set of frame horns on my 64. I had a winch bumper on from the po. it does take some fiddling around to get them back on there right
ron

[Jonboy]

if it's only the rear of the frame that is out of square and you have already cut down the later frame, why not just the 65 frame and section in the rear of the 68 frame? If the rails at the rear are the same (should be) wouldn't that work to get what you need accomplished? It seems like that would be easier than jockeying around cab mounts and such.

[SCOTI]

Originally Posted by Jonboy

if it's only the rear of the frame that is out of square and you have already cut down the later frame, why not just the 65 frame and section in the rear of the 68 frame? If the rails at the rear are the same (should be) wouldn't that work to get what you need accomplished? It seems like that would be easier than jockeying around cab mounts and such.

In straightening the frame, the dimensions between the suspension mounting points are now off (front c.member holes diagonal to the trailing arm c.member holes); they weren't before.

The front drivers side frame horn is also tweaked slightly but that was a fix I new I had to do.