Or just buy some dually spacers form Arrowcraft, bolt them on and bolt on the budd rims, no need to mess with a whole rear end swap.
It's been discussed before, adapters like that are good for the front but for the rear they're generally not a good idea as they move wheels load plane further out and pretty much right right on top of the outer bearing (instead of right between the outer and inner like it's from the factory) - this works fine for just towing a trailer, but if the truck gets loaded down heavily on regular basis it may cause premature wear in the outer bearing. There are of course those who've been running adapters in the rear for years and years and have no issues whatsoever, but I'd personally do it right the first time and be done with it.
Are you going for the look? load rating? or what?
FWIW, Ford de-rates the SRW rear ends to match the exact load rating of 2 stock-size 10/E tires. IMO, the SRW rear end can carry just as much weight as the DRW - perhaps even more - as the axle tubes are shorter.
Where I'm going with this is, I put 19.5" wheels and rubber on the rear of my E350. The wheels are 4500# rated, and the tires are 4850# rated. I'm confident that I can now safely load it up as much as the dually E350 cutaway. That cost me $1200CDN total and only the labour of swapping them on. You would drop that much coin for four 16" wheels and new tires - nevermind the dually axle itself or dually adapters.
Well, of course the SRW rear can carry the same load as the DRW, it's the same axle
The issue with the factory SRW configuration is, like you said, the wheels and tires - so did you put single 19.5s in your E350? That's pretty interesting setup, do you have any pictures?
the super duty rears definately wont fit.
True, the frame of those is narrower than the pickup-body frame, so it's likely the inboard tires will run on the leaf springs. The 14-bolt may be alright tho, depending on how far apart the in board wheels sit they may clear the springs, it's likely spring perches will need to be moved tho.
..... good luck
