1991 GMC bodywork, dually and 6.2 diesel questions!

[MR4WD]

I'm posting this in multiple forums looking for lots of feedback, so bare with me.

I'm looking at getting a 91 crew cab GMC. Last year for that style (V3500) It's pretty much the truck I've wanted since before I could drive, but it's single wheel. If I do purchase it, I WILL convert it to a dually, which shouldn't be a problem. The only thing I'm having difficulty with is finding aftermarket dually rims greater than 6" in width? I'd like to run 35's (the truck presently has 5 new 35x12.5x16's or whatever that works out to in metric terms) so I'd need to buy two more tires and 16x8" dually rims.

I realise that I could convert 6 or 7 16x6 steel rims to 8" fairly easily, but I'd like to run aluminum rims mostly for aesthetic reasons. I've sifted though a few websites, but manufacturers seem to concentrate solely on 16x6" wheel sizes? The other side of this is would a 35x12.5 run on a 6" wide wheel? I would guess no, but I've never seen or done this.

I can get outrageous deals on alcoa wheels, so I may go with (4?) new wheels and run a set of 36" michelins, which I could probably get for cheaper than a few new 35" bfg's. I'm aware those run acceptably on a 6" rim. While the tires will probably wear like iron, I find them a bit narrow for my tastes...

I have no requirement for an 8' bed, so I'll probably chop the frame and install a shortbox. Would dually flares fit on a shortbox? What sort of problems may I encounter?

I really have no experience with dually's in a personal environment. The truck I drive every day at work is a dually, and I usually make it my personal truck but I've never owned one.

Lastly, the truck has 60,000 miles on it and the original (no doubt!) 6.2 diesel. One of my work trucks had a 6.5. While quite enemic it was great on fuel, which is an underlying outline I have made. Down the road, I'll convert it to a 12 valve cummins and bomb it, but for now I'll settle for the fact it's got a 6.2 with an upgraded snail, down pipe and exhaust. What sort of power band do these engines operate in? The truck currently has 4.10's and a new 4L80E (with a 205!!). I shouldn't have a problem trading the SRW Dana 60 and 14 bolt for DRW versions, since everybody seems to have those. In OD, with 35's at 70 MPH I'd guess I'll be around 19-2000 RPM. Would the 6.2 cruise with a meagher load at that RPM? (a bed full of work gear for a few weeks) Or would it kickdown into drive all the time? An idea may be to trade up to 4.56-4.88s? I like to think of the 6.2 as a 350 that turns half the RPM, but I'm mostly unconfident and inexperienced with this motor...

Thanks from anybody who can offer insight with this truck,
Chad.

 

[K30CJ]

Sounds like a good project. I prefer the SRW myself. I'm surprised you'd rather have a dually up there with all the snow you surely get. With all the length, and the additional width of the dually, it could be a lot to handle in tight spots for everyday driving. I drive mine most everyday, but I am rarely in tight city situations. If you thought the 6.5 was weak, just wait 'til you try to work that 6.2.... /forums/images/graemlins/shocked.gif They do get great mpg though.

Anyway, mine has the Cummins transplant, so if I can help with any questions, just ask. /forums/images/graemlins/thumb.gif

 

[MR4WD]

We'll see what happens with the dually/shortbox set up first.

Got any pictures of the cummins in your truck? Know of any links for this conversion? What tranny are you using?

Chad.

 

[K30CJ]

Mine has the "famous" Getrag 5 speed manual. They have a bad reputation, but this is my second truck with a BOMBed Cummins and Getrag combo, and I have had no problems. I do tow pretty heavy too. Seems that most Getrag problems are oil related. Like not enough or the wrong type. Luckily, mine was just rebuilt before I bought it. /forums/images/graemlins/smile.gif

The best info on the Cummins is at TDR It's cloudy here, but I'll see if I can get some pics of the engine today.

 

[Chris_T]

[ QUOTE ]
I can get outrageous deals on alcoa wheels, so I may go with (4?) new wheels and run a set of 36" michelins, which I could probably get for cheaper than a few new 35" bfg's. I'm aware those run acceptably on a 6" rim. While the tires will probably wear like iron, I find them a bit narrow for my tastes...

[/ QUOTE ]

I would be more concerned about the sidewalls of the BFGs rubbing against one another and creating excessive heat. In this case narrower might be better.

 

[90blzr]

Man, I'd hate to see that SRW get converted. They are getting harder and harder to come by. Duallies are much easier to find. Why wouldnt you just buy a dually in the first place? /forums/images/graemlins/dunno.gif

 

[75-K5]

John...damn, if you ever want to get that crewcab off your hands I'd be interested! /forums/images/graemlins/thumb.gif

 

[MR4WD]

[ QUOTE ]
Man, I'd hate to see that SRW get converted. They are getting harder and harder to come by. Duallies are much easier to find. Why wouldnt you just buy a dually in the first place? /forums/images/graemlins/dunno.gif

[/ QUOTE ]

Stock blazers are getting harder and harder to find as well. Maybe we shouldn't modify those either?

 

[Can Can]

I don't wanna seem like a dick but this thread has nothing to do with towing or trailers. I'm gonna lock it but leave it for informational purposes only.

Just trying to keep things on topic, brother. /forums/images/graemlins/thumb.gif