80's D150; widest tire

I installed the 85 box on my 83 and was wondering what is the biggest (widest) tire you can run with the stock wheel wells. I was going to run a 315/60/15 but looking at the wells there is no way that big of a tire will fit without tubbing it. Whats the best way to tub? Using the stock tub and a filler or new tubs?

Depends on ride height and rim backspacing. Stock you can fit at least a 33x12.50 tire at stock height. Its under 31"
Do a quick search this seams to have just been discussed

my truck rubbed on the inside with 275/60/15's and i had about an inch inch and a half on the outside edge with 15x7 police wheels. just tub it

https://board.moparts.org/ubbthreads/show...e=1#Post7556391

My truck never rubbed with 275/60s. 15x10 Centerlines 4" backspacing.

I have 275 60 15s on the rear of my shorty. They are on 8" wide rims with standart offset. I do have some room on the inside if I played with widre rims with more backspacing. The best way is to get your tape measure out and do the math..

Thanks for the good info; I probably am going to tub it as I do want to run at least a 315/60/15 tire.

when you cut the full tub out leave the little rail along the inner edge to weld back to the floor.

i cut it right to the frame brace on the bed rail.

Thanks Mike; what did you use 2 stock tubs to make one?

I used 1 full set of tubs cut out of another bed. sliced the stock tubs down the middle.

this will let you tub it right to the edge of the frame brace on the floor botom.

over lap the tub edge and weld it up both sides and along the floor.

little bodo work and hand rubbing they turn out nice and have the stock look. just fat

the aftermarket tubs can be used also. depends on what you up to doing.

as far as rims.. with it tubed to the frame/stock width truck axle you can use a 10x15 rim with 7.5 bs with the 29x15x15 M/Ts (see ricksterhemi black truck for referance)

IIRC, Grumpy posted he runs a 10x15 with 4.5 bs.

my 12x15/a-body axle runs 4.5 bs 29x15x15 M/Ts with stock truck 43" perch centers.

I replaced the bulkhead and chopped the long bed floor down to fit the short box,then tubbed it flush with the frame

have fun drilling spot welds,there is a LOT of them thats for sure.

I drilled all of them after choping the bed sides off,across the rear end brace and corners are the hardest.

Thanks Mike; that looks like a lot of work, but the end results were worth it.

yes,lots of work. but I saved a ton of cash doing it myself.

I got the box for 75 bux,floor was shot along with the bulkhead but side were perfect.

the rust free 88-long bed from Kansas paid for itself 5x over on a 500$ investment.

I scratched up the rest.