I got a 1986 d150 and a 1988 D250 I was wondering if there was any different in the Frame. Thickness or size. I know there axels are different and other suspension parts are different, which I plan on moving the D250 suspension and Axel to the D150 but I’m looking to have the D150 tow similar to the D250 and not want to destroy or bend frames if they are different so thats reason I’m asking.

 

That's a tricky one..... It really doesn't matter what you do to your truck, the tow rating is based on the VIN the vehicle is registered with. If you use the D150 VIN, then you are limited by what it was originally rated to tow. If you tow/haul more than that, and have an accident, your insurance company can refuse to cover you, and the cops can hand you an assortment of citations for over-weight towing......

 

straight from the DIY thread stickied to the top of the 1st gen section

This was taken from the user MYSTERYMAN on Turbo Diesel Register forums.

"The frames from 72 threw 93 are basically the same at a glance but quite different if you look closely..

The 8" (some were 7.5") frame was used on all the cab/chassis models. It was also used on all the 1 ton pickups and select 3/4 ton trucks..

Most of the 3/4 ton and all of the half ton's used the smaller 6" center frame.

The 1st gen diesels 89,90,91.0 250, 3/4 ton used used the 6" frame but it was a bit heavier than the earlier gas version. You could order the 8" frame
if desired but most were called single wheel 350's rather than 250's

89,90,91.0 350, 1 tons used the taller 7.5 " to 8" frame. The 8" was a bit heavier than the earlier gas version..

In 91.5 the 8" frame was updated and is heavier than all the rest that came before it... This is hard to see with the naked eye. But quite obvious on the blueprints. It was updated and the 6" frame was discontinued due to breakage problems... in conclusion.....
All 91.5, 92 and 93's 250's and 350 diesels used the SAME frame ...

The exceptions.....2wd verses 4wd....The frames are the same except for the front cross member's and spring hangers....

Converting a 2wd frame to a 4wd frame is rather easy assuming that you have the 4wd engine cross member and 4 spring hangers...


Converting a 4wd frame to a 2wd frame is a whole lot of work !!!!! You have
to change the front cross member and the engine cross member.. Weld in the motor mounts. Mount the upper control arm brackets.... None of the holes will be pre drilled for you. You will have to drill them all yourself.. The tolerance for these holes is .125 (1/8") on center .. If you miss the mark you may never get it to take a front end alignment or track properly...
I would not recommend doing a 4wd to 2wd frame conversion to a novice
or back yard mechanic..

One last note..... If you need to replace an 89,90 or 91.0 6" 250 diesel frame. And if you can not locate a diesel frame.. You can use an early 7.5" 300 gas frame.. All the holes will line up for the most part...

Be sure to measure the wheelbase of the doner frame you buy...
Trucks that were sold as "cab/chassis" have longer frames than Pickuptrucks.

And dually rear axles out of "cab/chassis" trucks are NARROWER than the dually rears out of pickup trucks..

Dually rears out of "cab/chassis" CAN be used in most cases in single wheel pickup trucks.. You may need to change the gears to get highway speeds with the diesel.. 3.55 to 1 ratio is the best choice for all around use when using stock size tires.

I hope this answers all the frame questions"

 

The D100/150 std cab frame is especially thin gauge. Otherwise same section size as D250 std cab

 

Alright Thank you for the information. It’s all appreciated