The Stovebolt Site Forums The Parking Lot Big Bolts P 30 axle question

I found a p30 front axle with disc brakes bolt pattern is 7.25 but the center hole is 5.25 is there 1 with 4.75 center hole

No, they will be 5.25"
You can use newer wheels or accurately machine your wheels to o 5.25"

I would be happy to save you some time and headache with narrowing that axle and send you the brake components to swap your hubs over to disc brakes. You get to keep your original wheels!

With an original 2 ton axle the P30 spindle swap is pretty much bolt on, no axle narrowing.
It is another viable option.
As Your kit has advantages, the P30 also has advantages.

Grigg, I understood wrong. I thought you had to narrow the axle to fit under the fenders. It's good to know that it is pretty much a bolt on application.

Thanks for the clarification.

No problem. It's just reaming the old worn out P-30 spindle bushings to size to press the new bushings in that come in the 2 ton kingpin kit.
Then assemble draglink from off the shelf parts or a little fabrication, and a little fiddling with tie rod, shorten P-30 or reuse 2 ton.

The disc brakes this gets you are quite substantial and all as factory for the P-30.

Grigg you said off the shelf parts for the drag link do you happen to have part numbers. Also the guy wants 400. For the complete axle assembly is that a fair price

No, I haven't gotten to my own conversion and one conversion I know of was for a COE so different draglink stuff.
You can buy tie rod or draglink ends and various length adjusting sleeves from the picture books at NAPA, I'd start there.

By the time you buy an axle and buy new/rebuilt calipers, pads, rotors, seals, and possibly bearings you'll have some money in it. Doesn't leave much room to pay a lot for the axle.
I've bought them for about $100 but not recently, still I expect you can find them reasonably with a little searching.

My 1939 Chevy 2 ton COE has a 2 ton 1980 P30 front independent suspension with factory disc brakes & the older wheel bolt pattern. The truck was a 1980 Chevy step van (bread truck). The frame rails are identical to my 1939 COE's P30 frame rails. The axle width is also same as my 1939 wheel width. But with power steering, independent front suspension & power disc brakes. If I had chosen to leave my cab on the 10" pedestal it sat on originally, my 1939 cab would had mounted on the newer frame rails perfectly, even the holes for the older cab pedestal was in the correct spot on the newer frame. Everything would had hooked up with very little modifications, such as drilling holes for the step-vans hydra-boost master cylinder to mount on my firewall, & a hole for the step-van's swinging brake peddle rod to inter the cab. Only real modification would be to shorten your original steering column to except the linkage that brings it to the steering box, "original stepvan steering column linkage". Or you can use the steering column from the stepvan which also also mounted with no modifications.
You can find those older 1980s step-vans sitting around for next to nothing. But then you would also want to rebuild that front suspension? Or since the frame rails are identical, you could keep your frame & add the front suspension to your rails. But you will still need the steering box & master cylinder..... That's another option...
see my suspension in my photo alblum

I bet all IFS P30 front axles have 8 on 6.5. Solid P30's are more period correct for many trucks, owner's choice. Don't think 10 on 7.25 was ever on IFS.

Ed

They were, I see IFS about half the time or a little less when looking at the 5/10 lug step vans.

Grigg

Good to know, thanks, Grigg.

Ed

Are the frame rails for a 1946 2 ton the same as for
a 1939 2 ton COE? Jeffrey

Jeffrey, P30 frame rails should all be the same. Difference would be in the application. Mine is a COE, same as the 1980 truck was a step-van/COE. So the steering box angles up. A conventional long hood truck may have a different steering box, or at least it may be angled different? I believe other big truck makers use the same frame rails, but may have them wider apart due-to there axle & cab mount width. I don't know that much about them, I was surprised to see my 1939 was the same as 1980. I believe P30 frame rails are still used, the axles & cross members may differ.
I once saw a 1946 2 ton conventional restoration that the owner unbolted the original straight axle & mounted an independent front axle in place. I'm sure he needed to drill holes, he may had boxed the rails, I don't remember the details but it worked.

While the frames may be similar for different years and erras of trucks I'd be real hesitant to say "they are the same" for anything except the same body style/year range of the same size truck.
After that use your tape measure and judgement for comparisons.

For example the AD trucks the frame from about the cab forward tapers in narrower at the front, the springs follow this taper, they are not parallel. Later trucks usually have parallel front springs and frame rails.
AD trucks from 3/4 ton to about 2 ton have 36" wide rear frame, later model trucks standardized on 34" wide outside the frame rails.

I'm sure you can do some swapping and fabricating, and it's been done, but not usually as easy as is being made out here.

Grigg