Frame differences

[original balzer]

Some of you know about my crew cab project. For those that dont it started life as a 2wd and was classified or titled as a 3/4t. The frame is narrow on the rear like a 1 ton, its also alot taller than a half ton frame.
So I presume that crew cabs, all got 1 ton frames regaurdless of the fender badge.

Now heres where it gets complicated. On the blazer Im robbing parts from the hole for the front rear shackle mount is 2.75" forward of the front CAB mount, and about 2" up from the bottom of the frame. The cab mount has about 1" of frame under it. The problem Im having is locating the hole for the shackle mount to go through. The crew cab has about 3.5" of frame under the cab mount. I have them sitting side by side and can compair them visualy pretty well and its VERY obvious in the hight of the frame differnces.
IF I was to try to locate the hole the same as the blazer I would need like 9" long front shackles. But im not going to locate it the same as the blazer I want to move the axle about 3" forward and I have to compensate for lift.

I hope Im not confuzing everyone. Ill try to draw a picture to show what I mean. The blue is the differnce Im puzzled about. Ill figure it out Im sure, just kinda threw me for a loop and I thought I woudl point it out.

Balzer

 

[thatK30guy]

Actually, the 1 ton frames don't "add" height to make them "taller". The frame height just protrudes DOWNWARD instead of up.

If you were to slice approximately 3" off the bottom of a 1 ton frame, it would be very comparable to a K5, 10 or 20 as far as the location of hanger brackets go.

 

[original balzer]

Uh yea its about 3" taller overall (from the top down) than the K5 frame witch complicates locating parts that go UNDER the frame. The cab mounts seam to be VERY close to the same location if you measure from the top of the frame down. You just said it better than I could lol. Like I said Ill wear out my measuring tape and I WILL get it right. Just thought I would point it out so others would know. I didnt realize it at first, (just wasnt thinking on that plane I guess), and was realy confuzed about why my measurements were all screwy. Now that I understand why I can compensate for it.

Balzer

 

[dremu]

So I presume that crew cabs, all got 1 ton frames regaurdless of the fender badge.

Yes. The 3/4 crewcabs, I suspect, were just GM playing with emissions ratings for the DOT. Also, due to the increased weight, a sixpack needed larger springs, brakes, etc to get the same GVWR as a regular cab... so a 3/4 crewcab would be like a light-duty 1ton. ::shrug::

Now, as for your spring issues, donno what to say -- mine is staying a 2WD, so converting it from C20 (SRW) to C30 (DRW) was easier

-- A