Click on image for the lowdown. 
====
| | | Forums66 Topics128,035 Posts1,055,445 Members48,422 | | Most Online14,466 Apr 26th, 2026 | | AD Chevy Trucks Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
Lots of work on Brad's part ... pure enjoyment (and references) for you!
| | THANKS!
For helping keep this great
old truck web site
on the Internet for over 30 years! and not clogged down with Ads! Again, thanks! | | | | Joined: Apr 2009 Posts: 88 Shop Shark | | Shop Shark Joined: Apr 2009 Posts: 88 | Ok guys I want to hear your feelings on what I am thinking. I have found a 50 GMC 650 that I am thinking about mounting the cab on a 19.5 tired motorhome chassis. I will be placing a 453t Detroit and RTO 610 trans in this truck. I think it would be cool when done and I would not have to cut the body up too much because the truck already has a 471. I am going to use the original 471 for parts to fix my 51 640 GMC and then either sell or part what is left. Here is my question, am I taking a somewhat hard to find truck and destroying it or not. I know it took me a while to find my first one. I would like to hear your opinion on this because I was going to use a 350 GMC but this truck came along and I think it would look good when done. Still trying to decide whether to do this or not. Thanks Brad | | | | | Joined: Nov 2010 Posts: 1,159 Shop Shark | | Shop Shark Joined: Nov 2010 Posts: 1,159 | Sounds to me like a nice up-grade project! The guy that really knows this business is,of course,Grigg! got pic's?? | | | | | Joined: Apr 2005 Posts: 1,107 'Bolter | | 'Bolter Joined: Apr 2005 Posts: 1,107 | i see gmc 600 series trucks laying around quite often. actually there's a guy close to me and on this site that has/had one for sale. most of them were 426/503 gassers. i dont know anyone regularly feeding one of those so theyre parked. sounds like a viable plan. | | | | | Joined: Mar 2013 Posts: 176 Shop Shark | | Shop Shark Joined: Mar 2013 Posts: 176 | If it's what you want to do, do it. Most of the old rigs will just rot into the ground if someone doesn't take an interest and bring them back to life. There are a lot of trucks still out there, it's not like your taking the last one. | | | | | Joined: May 2005 Posts: 8,878 . | | . Joined: May 2005 Posts: 8,878 | Your trucks, your decision.
I personally would keep a 4-71 in a truck that came with one, and or upgrade to a 4-71T, not a 53 series.
19.5" tires under a 650 cab and fenders will look very much on the small side, not something I'd do. | | | | | Joined: Dec 2002 Posts: 2,549 'Bolter | | 'Bolter Joined: Dec 2002 Posts: 2,549 | Brad, The final decision is yours, but let me chim in on something. When I first met you, you reminded me so much of myself, when I was your age, it was amazing. I like you, had collected many antique trucks through the years, with ideas of restoring over half of them. I, as you may know, was working on 5 trucks at the same time. Well needless to say that approach doesn't work unless you have a boat load of money somewhere to draw from, & a lot of spare time. Here I am 25 years later, with not one finished truck to show off. Just had a bunch of incomplete projects. I came to the realization that the only way I was going to finish a truck, was I could only have "one" truck project at a time sitting around. That's why I have since whittled my collection down to one COE, & I have gotten more done to it, in the last year, than I have any other in multiple years. That being said, if I were you, I'd be trying to finish one of those Wrecker projects you have. Being in the Wrecker business, what better way to promote yourself. Now back to the question of a 600 series trucks you're speaking of, they were not that scarce, but were the least desired of the Heavy Duty GMC Line. The 700- 900 Big Cab trucks were more popular, & practical,because of the larger cab, & were also better looking. Medium Duty Customers, that wanted a Heavy Truck would order a 400, 450, or 470 series truck, so the 520, - 650 style trucks were kinda left out alot of the times. | | | | | Joined: Aug 2009 Posts: 184 Wrench Fetcher | | Wrench Fetcher Joined: Aug 2009 Posts: 184 | I'm all for original....but well done modified is fine by me as well.
To really answer your question I have one back for you.....What are you trying to accomplish? Why move it to a different chassis if you are going to change engine/trans anyway. Why not keep the truck & chassis together and swap engine/trans into it. You will have to not only fit the body to the camper, but also workout the engine & transmission mounts, drive line, figure out brake pedal, clutch pedal, throttle. Some of this may be easy, some can get quite complicated. I've heard that 19.5's look small compared to 20's and assuming this is correct it will in my opinion make your truck look 'off'.
I would say change engine in your truck as it sits and get rid of the camper. If you need better gearing you could start looking for a higher ratio rear end or get an auxilary to give you overdrive.
Also as a 33yo with 13project vehicles I agree with much of what Spanky said....granted I'm too stubborn to give up and am moving 900mi in the summer/fall, projects and all. I am trying to get my stuff road worthy, I personally don't care much about body work, just keep the rain out and feet off the ground. The stuff I drive are worse than most peoples parts trucks anyway. I know full well that I will always own more projects than I have time for.
Tad
Last edited by Jungerfrosch; 05/01/2013 2:22 PM.
1946 Chevy OS 1.5ton, 1955 GMC 3100, along with other various IH,Ford,Nash,MGB,.....
| | | | | Joined: Apr 2009 Posts: 88 Shop Shark | | Shop Shark Joined: Apr 2009 Posts: 88 | Well I feel a little better about my plan but Spanky you are absolutely right. I have several projects that I want to fix but never will so I have been slowly selling off some of my trucks. I am suborn too but I am also only 23 so I have some time to try to finish them. I am trying to decide what to do with this truck. I want to build a mini antique big rig using a bigger GMC for the body. I really need to sit down and make some more decisions on what I want to do. Basically I wanted to see if cutting up the 650 was a bad idea. Thanks Brad | | | | | Joined: Aug 2009 Posts: 184 Wrench Fetcher | | Wrench Fetcher Joined: Aug 2009 Posts: 184 | Something to consider is that basically the large old trucks are only worth about what they will bring for scrap value, as your 650 is not excessively rare then this probably holds true for yours as well. Using price as a consideration of value as a collectable you aren't doing much harm to the old truck hobby by "loosing" one more.
Good luck, Tad
1946 Chevy OS 1.5ton, 1955 GMC 3100, along with other various IH,Ford,Nash,MGB,.....
| | | | | Joined: Jan 2008 Posts: 4,961 'Bolter | | 'Bolter Joined: Jan 2008 Posts: 4,961 | I think everyone has summed it up pretty well. I have a half a dozen larger GMC trucks simply because I have been in the trucking business for over 49 years and my first big truck was a GMC. Just about all of them will start, run and stop. But I don't go out on the street with them. I just enjoy having them around. If I want to ride around in an old vehicle, I have a 1956 Ford just like my wife and I dated in.
As for the wheels, 22.5 are comparable to 20" tube required. 19.5 are comparable to the wheels that originally came on a 1 ton 60 years ago. In my opinion, 19.5 wheels would look goofy on a 600 series. I have 3 600 series GMCs. They look right with 9.00x20 or better yet 10.00x20 or 11x22.5 in tubeless. | | | | | Joined: Jun 2011 Posts: 5,096 Crusing in the Passing Lane | | Crusing in the Passing Lane Joined: Jun 2011 Posts: 5,096 | I agree w/ Grigg, keep the 4-71, put a turbo on it, use the RTO-610, find 22.5 wheels.
'37 GMC T-18 w/ DD 4-53T, RTO-610, 6231 aux., '95 GMC running gear, full disc brakes, power steering, 22.5 wheels and tires. '47 GMC 1 ton w/ 302, NP-540, 4wd, full width Blazer front axle. '54 GMC 630 w/ 503 gasser, 5 speed, ex fire truck, shortened WB 4', install 8' bed. '55 GMC 370 w/270, 420 4 speed, grain, dump bed truck from ND. Works OK.
| | |
| |