Does anyone know? How does a van chassis differ from a truck chassis?

[1975stepside]

I picked up a crappy looking G20 Chevy window van CHEAP, and want to build some sort of hot rod, so need to know how a van chassis is different from a truck chassis and what it can and cannot be used for. (I'll probably just toss the body)

MANY thanks for any and all info you can give me!

[jeffspower]

IIRC, no frame- unibody with the pickup (or at least similar) X- member front end. Rear end is wider than one in a PU. So, if you "toss the body", all that will be left is parts in a pile.

Does it have a tilt column?

[Srubydo1986]

well i know the center gill pieces are the same in the 80s. as for the frames im shure they are very much differnet never been under my freinds but the seem to be built so with stand weight and not twisst like a pickup frame. But as far as that not much more i can think of.

[1975stepside]

Hmm, guess I'll have to crawl under there and see if there is a complete frame, although I would think so as it is classified as a 1/2 ton with a 3/4 ton ratiing, from what I got when I looked up G20 van in wickipedia. Well, I guess I could always just saw the body off horizontally about rocker panel level. I have a new saw I've been itching to use.

[Ivan D.]

Bet it's a full frame, at least all the old ones I've see have been full frame. If it were my van I'd turn it into a crew-cab van, then toss a 14-bolt dually axle in the rear and drop a pickup truck bed over it

[1975stepside]

OK, I crawled under there today and looked. Yes, it DOES appear to have a full frame, although the frame material seems a bit skimpy, sort of like a frame made out of what appears to be almost large thick sheet-metal channel (when I say thick, I only mean thick for sheet metal, seems skimpy for a frame), it runs the whole length of the van. For the most part, it is straight and level, doesn't even "bump" up to clear the rear axle. Hmm, I guess it could be braced with some other channel beside it if necessary to strengthen it. As I said, it's hard to tell how thick the metal of the frame channel is, but they seem to have gone with fairly large but thin walled channel. But the "frame" does indeed run the whole length. REAL straight except at the front and REAL flat.

[1975stepside]

Mostly I am wondering about the difference between a van and a truck in the front end area. The van seats are right up over the bumper almost, an just about in FRONT of the transmission, while a pick up trucks seats are waaay back behind the engine. So...I wondering how differently the suspension may hook up etc the steering and so on. That will pretty well determin what I can make out of the thing....

[DirtyLarry]

1975stepside,

Like I was telling you in your other tread, G vans from 1970 through 1996 did not have frames (27 years of the same body style). They were all unibodies…..except for the rare heavy duty cut away cab designated as the P/G 30HD offered from 1992 – 1996. Those were G van cut-away cab chassis mounted on P-chassis frame rails. They are obvious to spot as they have full tilting hoods and sit extremely high.

What you think is a “chassis” or “frame rail” under your van are the horizontal body supports that are made of stamped steel and spot welded to the body. That is not a true frame rail. The front cross-member and engine cradle is not a common bolt in part between vans and trucks of that era although the upper and lower control arms are. The rear axle is wider on the vans as well.

Back in the day of the unibody G-van, the GM Body Builders Guide did find it acceptable to cut the body off behind the front doors and use the van floor as a flat bed for upfitting bodies (RV’s, high cube bodies, etc). Most cut-away’s for RV and Commercial were built from GM as “Cut aways” with extra cab supports.

Believe me, I worked as a FedEx fleet tech during college and twisted wrenches on many many early 90’s G-30 delivery vans then moved to Detroit to work for the General where I work with the sales, service and distribution of the RV and commercial truck market. G vans did not have frames before 1996.. 1996 to 2002 G vans are full frame and 2003 to current G Vans have the same basic hydroformed frame rail design as the GMT800 Silverado/Sierra platform.

Keep the van and convert it to 4x4 for a cool camping rig. I just saw a 1979 Pathfinder 4x4 converted G van that sold on evil bay for $750. Dang….I wish had bid on that thing. I kinda have a strange attraction for G vans.....must be because I am a product of the 70's.

[1975stepside]

Yeah, Dirty Larry, I think you are right! As I mentioned previously, I DID wonder about the "frame" I saw, as when I tapped on it, it just sounded like sheet metal, but it did LOOK like a frame, albeit straight as railroad tracks...

I talked to another guy who seemed to know quite a bit about them and he confirmed what you already said on your previous post: that it isn't really a "frame" under there, just sort-of a frame....

Well, I guess if I wanted to toss the van body and use it for something else, I could just find some steel channel to weld onto both front and rear suspensions and make a frame out of....but on my other post a lot of the guys are saying to just redo it as a van all over again. The main problem with it is that it is a WINDOW van, and was never anyone's idea of "cool" in the first place, but who knows what could be done with it? When I first got it, I only bought it on a whim, and I got it on the cheap, and simply planned to scavange the engine, tranny and rear-end from it and any other parts that might be useful as I paid less than the sum of the parts might be worth, just to "get it outta someone's yard". I also managed to get it with title, which can certainly be useful. After all, it came with a "running" 350 engine w/4 bbl carb, a TH350 tranny, posi-track rear end, 4 nearly new tires and a WHOLE LOTTA sheet metal and glass, hah hah!

But - you know how it goes, I got a LOTTA respect for any old cars and trucks in decent enough shape to fix back up, and it's hard to wanta take a chop saw to the big beast, as it really isn't all that bad of shape for it's age of 31 years!

So far, I've been able to start it up by pouring gas down the carb. I pulled the fuel line of off the Quadrajet carb and there was ZERO gas coming through from the fuel pump, even though I had poured about 5 gallons into its 36-gallon fuel tank. I picked up anoher fuel pump, got the old one off OK, but have been having a beast of a time trying to install the new one, just hard to reach under there....if anyne knows a trick to succeeding at that, please let me know! Also the rubber fuel lines to the fuel pump were really rotted and when I pulled the pump off, they pretty well crumbled.

So...I've gotten some new hoses, not installed them yet (as I mentioned, CAN'T seem to get the fuel pump "in there" AND hold the tension against the pump arm AND tighten the bolts, all at the same time! Seems like I need either three arms or a prehensile tail to do the job!).

Anyhow, I was wondering WHY the gas I put in the tank hasn't been leaking out yet. Maybe there are some more rotted rubber lines pinched shut back at the tank? Do YOU know, seeing as you've worked on these things a lot? Please give me any tips you can on this beast. I wanna get it at least running on it's own before winter really hits hard in this part of the country. Thanks!

[Pyrotechnic]

Get some extremely dark limo tint (5%) for the side windows and you will be in business.