The Stovebolt Site Forums The Shop Area General Truck Talk 3/4 ton vs 1/2 ton frame???

Is the frame for both the 3/4 and 1/2 the same or is there a difference? I have a 3/4 ton with the 8 lug wheel pattern and would like to change all that and make it 6 lug 1/2 ton.
TIA
Don

What year truck??
The Advance Design series 3/4 ton frame is longer and the back half is narrower than a 1/2 ton. The fronts are dimensionally
the same. I believe the 3/4 frame is a little heavier ga. is all.
A 1/2 ton front axle of the same vintage will bolt in.
I do know that a Task Force series 1/2 ton rear spring pads are within 1/2" of the 3/4 ton rear...close enough to make it work.
Most other donor rear ends will need the spring pads relocated.

I second that the 1/2 ton axle of the same vintage will bolt in. I wanted 5 lug disc brakes for my 52 3/4 ton truck so I swapped out the 3/4 ton front axle for a 52 1/2 ton axle I got with my truck when I bought it. Was the easiest swap I ever did and all I swapped was the axle. The 3/4 ton steering and suspension parts all bolted/mounted up to 1/2 axle no problem. The only difference I seen is the width of the 1/2 ton axle is slightly smaller than the 3/4 ton axle, just about a inch or two. The distance from center of leaf spring mount pad to center of leaf spring mount pad is the same on both.

These are both 49 trucks.

I would suggest changing to an open rear instead of using the 1/2-ton closed driveshaft on the 3/4-ton frame. Get something from a Task Force or later six-lug truck and the conversion will be easier than trying to make a torque tube work on the longer wheel base.

Actually, you already have an open driveline, at least at the axle. The torque tube only goes back as far as the carrier bearing. You should be able to get a u-joint to connect the driveshaft to a 55-or-later rear axle.