Ok, I'm all about the SFA Chevy's & GMC's. I've got a 1983 GMC K-2500 (4x4 for those of you that don't know what the "K" is for) It's got a 400 small-block in it, followed by what I think is an SM465 (I've wirebrushed the side of the tranny and have got some numbers, can anyone help me there) an NP208 follows the tranny, and then a 14-Bolt Semi-Floater, yes this a 3/4 ton truck, and yes I'm sure it's a semi-floater, much to my dismay and extreme displeasure. The front is a 10 Bolt, recently refitted with WARN Premium Locking Hubs.

Now for all my questions, which asside from my tranny, don't involve this truck, it's our other one that I need help with. My dad picked up (at an auction for $3k) a 1986 GMC 3/4 Ton Camper Special Sierra Classic, so it's fully loaded, with Power Windows, Power Door Locks, Cruise Control, and AM/FM Digital Cassette. It's got a 454 in it and Turbo 400, just one problem, after that there is no 208 like there should be, or SFA. It's a f##king 2 wheel drive. This truck is straight, no rust, no dents save for one small one in tailgate, strong as hell, low miles, and my dad doesn't want to get rid of it.

I've been searching online for any documentation involving a 4-wheel drive conversion. I need to know if the frames for a 2wd and for a 4wd are identical, down to the factory holes. Are they drilled for 2wd & 4wd when they come out of the factory, or not? I've been under it lately, and have been taking stock in this project. There's a large IFS crossmemeber that's going to need to go, the motor mounts are on it so they need to be relocated to the frame like on the 4wd's. I need to get a smaller crossmember like the ones found on a 4wd to put in its place. Now here's the catch, this entire conversion must be done with genuine GM parts, no fabrication. My dad wants to use the spring perches and everything off of a wrecked truck he's going ot go find elsewhere. That's why I need to know, if the frames are identical in 2wd & 4wd. The good news is, I've almost got him talked into Dana 60 for the front to go with the 14-Bolt Full-Floater in the rear. But my dad is absolutely anal about using stock equipment.

If your truck is a manual 4 spd. with a granny gear it is a SM465. That tranny was OE for that year.

The frame rails themselves are identical between 2wd and 4wd. The problem is that when you get done removing the front crossmember from the 2wd truck, all that is left is the small cross piece that the brake proportioning valve is mounted to. So you will need to get all the cross members from a 4wd frame and bolt them in. Also the rear spring hangers on a 2wd are different from those on a 4wd. The frames for 2wd and 4wd do not have holes for both setups so new ones will need to be drilled. The only thing that is the same (i think [img]images/icons/crazy.gif[/img]) is where the steering box mounts to. The problem with trying to put the spring hangers and such on a 2wd vehicle is getting everything aligned properly. It can be done, but i would get a donor frame if i were you. I tried to do this exact thing to a 2wd C30 last summer. I ended up just getting a 4x4 frame, it made things much easier.

Ok thank you logan_ut, that clears that up. Yes, it's got a helluva granny gear, I read somewhere that it was like 7.xx:1 or something close to that. I was looking around one day and I discovered that a 5-spd was an option in those years, is that an SM465 with OD or what?

73K20, thank you also for the project help. Yeah, my dad and I were considering finding a donor frame, since our body and bed are in really good shape.

Also, something else I've been toying with in my head, are the housings the same for a 14-Bolt Full-Floater and a 14-Bolt Semi-Floater? I'd like to have a full floater in the rear of my '83, but I'd also like to do a disk brake conversion on it. I'f I get the 10.5" internal parts out of a FF, can I put them in my SF housing and go from there with a disk brake conversion for a FF?

This may seem like a dumb question, but who made the sm465?

No, the housings are completely different between a FF and SF. You would need a completely diff. rear end. And TSM makes a diff conversion for both housings.

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It's got a 6.55 first gear. Muncie made the SM465. Muncie also made the SM420 which had a 7.00 first gear. The 420 was end-of-lifed in the late sixties.

I don't remember what the 5 speed manual was. They didn't use it for long. It was more common in K5s from what I understand.

The 14FF and the 14SF look similar other than the case on the SF has more rounded edges. However, if you measure them they are completely different. In other words, no, you can't change the carrier. Not to mention the fact that the 14FF uses a lot of different parts outside of just the carrier.

Ok, well thank you all for your input, I appreciate it. I'm definately going to be part of the bulletin board now, it's addictive as heck. I spent 2 1/2 hrs the first night, then about 7 hrs the next day just following peoples links, and learnig more on SFA Chevs. It's great. I must add something for peoples benefits, I found a website, www.car-parts.com it is a junk yard search engine, it boasts being able to find 45 Million differnt parts, any state, all across the US. Pretty cool, I played with it for a little bit, and found a few 4wd frames for that project my dad and I have. Even found some V30 frames. V30, unless I'm mistaken, is the designation of the Crew Cab Long Bed 1 Tons that came out late 80s early 90s, correct? What a sweet project platform that would be. I can only dream about what I'd do with that.....

Dana 70s Front and Rear, I don't want Rockwells, too impractiacal for me, I'd throw a Duramax Diesel in it, have BANKS draft up a twin turbo system, run dual 3"-4" straight stainless exhaust up through the bed right after the cab. Prolly use the 6-Speed tranny that's available on Duramax's today, unless there's a better one out there? For general intents and purposes I'd prolly use an NP205, again, unless there's something else better out there. Put about a 6" Lift or so. Put Bushwacker Cut-Out Fender Flares, 37x12.5x17 Wrangler MT/Rs on 17x10 Mickey Thomson wheels (haven't deicided which model). Do the interior, leather, out of a 2002 Suburban with 4 Captains chairs, and billet dash. I'm thinking the GM color, Sunset Orange Metallic, or the Metallic Indigo Green. No flames, no gawdy monstrosity of a show truck, just a nice well built machine. I'd have the running gear and frame all powder coated dark grey, not black, too common, just want it to stand out a little bit. I'd have the bed and wheel wells armor coated. Just basically build myself a nice capable land yaght. Maybe look into the new Delphi Quadrasteer system to take a little outta the turning radius.

Now that I'm done invisioning my dream toy...

Go check out the ones at www.mattracks.com, I've already downloaded all of their vids.

[img]images/icons/tongue.gif[/img] I had a "pet" 1978 3/4T that I was considering converting to FWD, and I had decided that it was TEN TIMES EASIER to swap the frame. That way you get to re-do the body mounts and repaint the frame and what you end up with is a better unit all the way around. Have you ever seen the insides of the 14 bolt FF rear axle? The pinion mounts on THREE bearings not just two, and the ring gear is massive. When we made a trip last year towing a HUGE heavy trailer behind our 1980, we weighed 20,000 pounds and had to cross the Rockies after we crossed the Sierra Nevadas. I was so nervous about putting all the HP through that rear axle for those long pulls up grades that I installed a temp guage in the axle. The highest it got was 265 F, NO PROBLEM. We also split the NP205 so we have two levers now and eight, useable gears in 2WD. WHAT A TRUCK!!![img]images/icons/smile.gif[/img]

You guys sure about that 5 speed available back then? I've seen stuff about how the Getrag in the 88 IFS trucks was the first OD manual GM used, not to mention I've never heard of it or seen it anywhere, here, <a target="_blank" href=http://www.ColoradoK5.cim>www.ColoradoK5.cim</a>, the mags, trucks around here, anywhere.[img]images/icons/tongue.gif[/img] Just curious.

Ok, I went back and looked in my Owner's Manual (I remembered that that's where I saw the OD Tranny) it's a 4-Speed OD. Looks like this. Also appears in my '86 Owner's MAnual.

R````1````3
|____|____|
`````|````|
`````2```OD

Sorry 'bout the accent marks, had to use 'em to keep it from collapsing. Anyway, has anyone ever seen/owned one of these, what's the gear ratios in it? I don't think I've ever seen one. Oh and another thing, ot all those out there that have a Tach. to the right of their speedo, YOU ALL SUCK, I hate the 4" fuel guage, I've got a little bitty blank spot down in the corner that owuld be perfect for a fuel guage, but NOooooo, GM just had to give me a monster sized fuel guage....