The Stovebolt Site Forums The Parking Lot Big Bolts New Toy with some Questions...

Hey, I just purchased a low mile (28000 original) one owner 1963 GMC 960, V8/4spd, 2spd rear, Dayton wheels, Good Brakes, runs/drives nice, was last safetied & registered in 2005...has original Power steering and power brakes, which I think are rare options in these (please correct me if I'm wrong) also has Chrome Grille & Bumper, Mico brake Lock, PTO, Dual Gas Tanks, 23000 GVW....it also has the straight front axle, not independent torsion bar front suspension (like my 63 GMC Bus) Not sure how to post a pic here, but will try....still not sure how to post pics....my questions are 1. Has anyone swapped in 80's GM P30 straight front & rear axles?...I also have mid 90's GM 3500HD front and rear axles.....I'm also considering Swapping in a NV4500 5 speed overdrive trans, from the 3500HD...I'm not looking to work it too hard or anything, just going to be pulling my 2 car trailer (40ft) or 36 foot camper trailer....

Welcome to the Stovebolt

Sounds like an ex-fire truck.

What engine does it have?

What body does it have?

Put your pictures on a photo hosting site and post the link here for us to see.

Mike B

The one issue with swapping axles from a smaller truck into a larger is that the wheels will not fill the wheel wells as well. In my opinion it makes the trucks look kinda goofy a lot of the time.

Why are you looking to swap out axles or transmission at all? You could add an auxiliary overdrive to get you higher road speed a lot easier than changing axles or transmission. Also going smaller axles will reduce the load capacity to that of the 1ton they came from. I would change out engine and trans before I would swap axles....I just can't see reducing the capacity of the truck....even if you aren't planning on using it.

If you have 20" spoke hubs, 22.5 rims will be a direct replacement, and will get you radial tubeless tires along with a greater selection and availability. 10x20 and 11x22.5 are the same diameter tire.

I would think that for the size of truck power brakes would be standard. I could be wrong though, but it seems like a lot of weight to stop without assist. Power steering would be more likely to be optional though.

Tad

First figure out what you want the truck to do and then what you need to do to the truck to accomplish that. Might be the truck is pretty well suited as is, or with only minor changes.

If it comes to it is this the sort of axle swapping info you were looking for http://www.stovebolt.com/techtips/bigbolts/p30swap/
Perhaps in combination with this? https://www.stovebolt.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=725027#Post725027

Grigg

the 3500HD GVW is 15000 lbs, more than enough for my purposes, and the axles have the 10 lug rear/5 lug front, with the 19.5 inch wheels (and stainless simulators to boot) with the flared fenders, I'm thinking (hoping) there would be no narrowing of the front axle nessesary. I would like to lower the truck down some (definitely removing some springs, or all and use the 3500HD springs and hangars if possible)....if needed raise up or lose the running boards...I don't want the truck too low, I don't care for the lowrider look, and it's not practical for my use or our roads. I just want it easier to jump in and out of all day.....basically want a Nice Looking Trailer Puller, that is Practical and safe at highway speeds...in the future I may tackle a 4BT conversion, but that's far off. Yes, The truck was a fire truck, then donated to the municipality and was used with a flatbed for a few years, until I acquired it as a Cab & Chassis. Another option, itf the wheels look small in the wheel wells, is to go with 1/2 ton front fenders with smaller wheel wells, if the axle/tire will fit inside...if it looks like it is going to be a difficult swap, I may just look for other options, like a newer 2 ton axle set, with budd wheels...but would rather use what I already have. Will do some measuring in the next day or two I guess and see what things will look like. I was hoping that someone had already done a similar conversion on a truck like mine, and had some input. Also, my truck already has 11R22.5 tires (in front anyways, the rear still has 900/20, but I do have a set of 4- 11R20 like new here on a Bus.

it has the 327 engine, 4speed trans, 2spd Rear axle, I bought it as a Cab & Chassis. It was originally a Fire Truck, then it had a Flat Deck for a few years. All Glass is Good, including windshield, interior is nice, Cab is like new, pass fender has a couple small rust spots, Drivers front fender, up ahead of the wheel is quite rusted, not sure why, But I have a PERFECT set of front fenders here on a 62 GMC Bus, also a 960. That is last resort though, as the Bus is a shorty, and in fantastic shape.

check out the links in my reply above.

Grigg

Grigg, I have checked out your links, today, as well as a few months ago, full of great info (actually it is saved on my laptop) I like the spindle swap with sleeve idea, but am hoping the complete axle swap will suit me better, as my truck is pretty wide...I'll post any info/progress/measurements as I go...am heading to pick up the truck this eve...I hate to make a offsite photo site to link pics, as I see a lot of dead links on the site, and am guessing they time out quick, or sites vanish, etc....plus with dialup it takes a long time to do...

"as I see a lot of dead links on the site"

If you click on a webshots link, you are right, they are gone. There are a lot of threads with these links that are unfortunately dead. Webshots really screwed over a lot of people by changing their format or what ever they did. I had well over 1800 pictures in many albums. For what its worth, I just opened a Photobucket account and it was pretty easy to do. Links to pictures instead of have the actual pic in the thread safes big time space on the server (I think thats the technical explanation). It helps the site!

Yes, I understand the reasoning for just having links for pics, instead of the actual pics in the posts, saves server space, and also saves time loading with dialup internet, or data while loading on the phone. When I get back to the city I'll have high speed and get some pics loaded on photo bucket or something......
....So I did some measuring on the front axle/spring spacing, and I get 32 inch center to center, which is good news....I measured my spacing on my 86 GMC 3500 4x4 dually with the dana 60 front diff, same thing @ 32 inches, would pretty much bolt in (as close as one would expect anyway, now I'm considering 4x4 of course)....also, my 3500HD straight front axle has 33 inch spring spacing, center to center, but has very wide pads, and more than enough room to drill new holes....so now I have some options, if I decide not to stay with the stock axles......also, more specs on my truck, it has 175 inch wheelbase, 102 inch cab to axle...