GM 10 bolt identification

I have an 8.5" 10 bolt rear end with an open carrier and a 3.42 gear ratio.

From axle flange to axle flange it is 58". There is a stamp on the axle tube XFP 172 1.

I have looked thru a number of GM RPO codes and the only XFP code I find is for a 225/18 rear tire option.

I have no idea where to start. (and maybe it does not really matter). When I bought the 1950 Chevrolet 3600 the rear end was installed.

Just wondering.

Scott

 

G-body cars are 58" wide. Can you tell if brackets were removed from the axle tubes or housing?

 

pictures really help....several of them, from different angles, including all of the rear end and brakes. Well lit, in focus, are a bonus.

 

This may help , http://www.pontiacpower.org/74axle.htm

 

That chart is closer than any I have seen. I see the XE but not the XP. The ratio is correct.
The original plates/perches were cut off to put leaf springs under the 50 model truck. One side is clean and smooth and the other side looks like it had a perch or leaf spring saddle. No ears or tabs for a link type suspension.
The brakes were already gone, just the backing plates.
I will take some pics this afternoon when I am out in the shop.

Thanks.
Scott

 

Pics will be handy. If it was a g body and they removed the four link mounts there will be obvious cut marks on the center as the upper arm mounts were cast as part of the housing. The other possibility is it's from a five speed 4×4 S10. The 4.3 5 speed trucks commonly got 8.5"s

 

I should mention on both those applications common really doesn't apply to 8.5" rears as most of the overall production got 7.5"

 

Night shift lasted longer than it should have and I didn't make it to the shop this morning. I will shoot some pics this afternoon.

S

 

This is the center section. The brakes have been removed and it is 58" from axle flange to axle flange.

This is a project that makes people want to search out the previous owner and say mean and nasty things to him/her. The running boards were welded to the fenders pretty much ruining (nearly ruining front and rear fenders along with the running boards. I guess he wanted a 1950 model 3600 uni-body truck). The body mount bolts had tack welds on the threads. The bed strips were welded to the frame/homemade rack. So it has been a booger-bear getting it apart.
The rear studs had to be cut off. It looks like they ran standard lug nuts up on a metric stud or something along those lines. The Kobalt 24V would not break them and I was hoping the 3/4" air gun would snap the studs. Neither happened so I resorted to the hot wrench.

The knurled section of the stud matches up to a metric stud. I am not sure what 10 bolt I have, maybe even from a newer model truck? Not sure.

Scott

 

I don't see an abs tone ring so I'm going to ***ume g body. Really need to see the top of the other side of the center section to be sure

 

And what size studs did it have?

 

And is that transmission cross member from the same truck? Looks like a g body cross member lol

 

pics of the whole rear end might help, and the ends, etc. If it has GM gears they have info stamped on them, including date and ratio.

 

It is a 3.42 open differential.
I will take a pic of the top side this afternoon.
The crossmember is from a 2nd gen Camaro.
I had to cut the studs off. I knocked one out and the knurled section matches up to a metric stud M12 threads.
I have found some XE codes but not an XPF stamped code.
More pics to follow.
Scott

 

With M12 studs it's definitely not from a full size truck

 

Today I see one on Marketplace that has the same brake line fitting just above the pinion gear that is from a 92 Silverado. I think it is going to be closer to that year model truck rear.