Are the GMC frames taller then the Chevy frames?

[OldJimmy57]

I thought once I read on here that the GMC frames were 7" tall verses the Chevy's being 6" tall. I tried searching but found nothing. Does anyone remember or know for a fact that this is true or false?

[T Hilde]

They get taller as the series size goes up. 1/2 ton is shortest, then 3/4 ton is taller. I don't have the link handy, but there is a restoration pack that gives details on the different truck frames. Hopefully someone will add the link before I find it.

[57ToyBox]

So many variables fall in to play. As T Hilde says the series of truck is a factor 1/2, 3/4,
As a rule. They shouldn't differ by much. Many of the same model years, their parts are interchangeable. ie: shocks,springs.
Another variable is wear and tare. You find 2 same model yr trucks 1 chev 1 gm and they may differ in height because of their history. One maybe lightly used the other maybe be lower cause it is tired cause it was more heavily used

[OrrieG]

Use the link in my signature and look for "restorpacs" or something like that click on one of the 56 or 57 TF truck spec manual. There is a table in there under frame dimensions that gives all the dimensions and gauges of the frame metal. As the trucks get heavier the metal thickness, depth and flange widths increase. There is also a table that lists the different spring sizes and configurations, cab inside dimensions, and lots of other good stuff. I have never heard that the actual frame dimensions are different between gmc and chevy, only how some of the sheet metal and brackets are attached.

[mr48chev]

I've got a GMC frame out in front of the garage now waiting to become a 48 Chevy frame. Outside of the front crossmember and it being a long wheelbase 1/2 ton frame I can tell no difference between the two. The big difference is in the front crossmembers. You need the crossmember for which ever nose you intend to run.