Im considering doing the cummins swap into a crew cab. are the frames basically the same. Can the crew cab handle heavy duty pulling? Is there any how to do threads for tihs swap

 

I posted info from mysteryman on a previous post. Maybe you can find it. I don't have the time and am on the panamint resort's wifi in death valley. But basically he said the 1992/1993 club cabs are the heaviest frames dodge ever made.

 

Search my brother and you will find. There's been a few crews done recently and you probably know that to use the club frame for a crew cab you will have to either use a body lift or modify the rear floor to clear the frame. The club frame is larger from behind the tranny/t.case mount back. The front section is the same size. Somebody else will have to chime in on the load capacity of the crew frame. Johny5 has a real nice crew recently finished and a thread with lotsa nice pictures.

 

I've got quite a bit of info posted on the crewcab blog in my signature. I have not updated it lately, though.

The crews have a 7" channel, where some of the older ctds had 6" frames under the cab.

 

Our dually has towed campers and cargo back and forth to the Southern states several times.

 

i tried to research but couldnt find anything official, i guess you could go by the factory ratings and compare the two

 

If they are both in the same condition rust wise I would use the crew cab frame. Either way you need to remove or lift the body no matter what you choose because the odds are you have at least two or more body mount frame brackets busted.

 

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 Pickup trucks.

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

 

Thanks alot! So how would the crews fit into the above info? Pre diesel so 6in frame or 7in frame

 

My crew has the deep frame. It is a 1977, 4x4, shortbed. It originally had a 318, auto, 203, full-time with a dana 44 front, dana 60 rear.