700 to 350 turbo

[84chevk10]

I posted on here about putting a 454 in my 84 K10. Well it's going to happen, the 350 is 1 sick puppy. When I do it, I'd like to get rid of the 700R. That will be the next thing that takes a crap. I have to find a 350 turbo core, refresh my memory on which one. Can I use the 9 inch tail housing trans? Also, what is the deal on the adaptor, I'll need one to keep my driveshafts, right? It's been years since I fooled with these trucks, but we used to use the 9 inch type and cut so much off the tail shaft and I was thinking it was in the K series but I could be wrong. I have 3.08's and 11.50 tires, so don't really think I need the OD anyway. Also I still need a tail housing for my 208 transfer case if anyone has a extra. Some info and where to get the adapter would be appreciated, thanks.

 

[1987 GMC Jimmy]

I have one little nugget to add. Make sure you get a TH350C core (1980+) so you can retain your lockup. I don't know a lot about the 350's, but I was under the impression that the output spline count, tail shaft pattern, and driveshaft yoke are compatible, especially considering you want to mate an NP208 to it all. If you wanted to bypass an adapter, the crossmember would have to be translated forward, and a new (or used), longer driveshaft would need to be acquired because the 350 is shorter. I wouldn't cut and modify because you want preserve correct geometry and smooth centrifugal exertion which applies to output seal, universal joint, and driveshaft longevity. I'm certain there's an adapter out there to bring it all even, but I imagine it'd be cheaper to scavenge a junker with a similar setup and move things around. It's a shame you're not in Mississippi, buddy. My brother has the whole setup you want, and he's never gonna use it.

 

[84chevk10]

There's nothing around here, early 350 cores are scarce. Square bodys arn't to plentifull either. Back when scrap went sky high, everybody scrapped a bunch of good iron. A buddy of mine hauls crushed cars for several salvage yards. He was getting loaded 1 day and a old man come driving in, in a 78 chevy 2wd 3/4 ton, 454, 400 turbo with 78000 miles on it. Needed a front bumper and some sheet metal. Sold it for scrap, buddy bought the engine and trans for $350. They wouldn't sell the complete truck. Stupid crap like that is why there's no used early stuff. Now a complete big car complete brings a $100.

 

[Swims350]

if it's going into a 4wd you can get any th350 and buy the kit online for like $190 has the right shaft and spacer to put it in place of a 700r4. I actually think the 6 inch would work with just the spacer, I have to wait and see on that as I might try it on my 83 I just got.

The transfer case adapter is the same for a 700r4 and a th350, because I did this swap in my 88 k1500 obs it had a 241 c case and I put a th350 in place of the 700r4 that was in it when I got it. I also need to do the same to my 83 as there's no trans but it has a np208 case and adapter

 

[1987 GMC Jimmy]

There's nothing around here, early 350 cores are scarce. Square bodys arn't to plentifull either. Back when scrap went sky high, everybody scrapped a bunch of good iron. A buddy of mine hauls crushed cars for several salvage yards. He was getting loaded 1 day and a old man come driving in, in a 78 chevy 2wd 3/4 ton, 454, 400 turbo with 78000 miles on it. Needed a front bumper and some sheet metal. Sold it for scrap, buddy bought the engine and trans for $350. They wouldn't sell the complete truck. Stupid crap like that is why there's no used early stuff. Now a complete big car complete brings a $100.

That just burns me up. The same happened here to a smaller degree, but I feel like it affected older imports and older domestic cars more than older domestic trucks. Too many people still depend on Square Bodies and even the preceding Action Line trucks for something like that to happen. That's just GM trucks and SUV's. There are a ton of seventies Ford trucks and Dodge D-trucks still making the grind every day because folks either cannot afford something newer, they appreciate how long it's lasted them, how well it was built, and lack the desire to cash it in for a few bucks, or both. I guess it's kinda Cuban, but I like it. Only problem is, sorta like you, there are only a handful in junkyards because they're all on the road or in someone's garage. The only places that ever have them are more urban junkyards like in Jackson or New Orleans for me. Baton Rouge has had a small spike because of cars getting flooded earlier this year, but I know that's extraneous information for someone so far away. Anyways, I understand your dilemma, and I hope you receive the info you need.

 

[84chevk10]

Thanks for the info. I wish I could find just the adapter, you can make the tail shaft work if I remember right. We used to cut like a 1 1/2 off but I couldn't remember wether it was the 6 or 9 inch housing. Older is better, I'm layed off and also have some health issues, so I sold my 07 1500 hd and bought this truck and paid off some bills. I love these old trucks anyway. I got a 72 chevelle that I pay 68 cents in taxes on a yr, antique tags, so I spent the $100 to put them on this truck. Taxes and insurance on the 07 was crazy. I got to get this thing going, I'm driving my old work car right now. Anyone out there with just the adapter or know where I can buy it separate? Great site by the way.

 

[Swims350]

I'm pretty sure I've got 2 spacers here if so I'd sale ya one. it's a 6 inch trust me 9 would be too long I would think. I have an np208 case and without the spacer, but having the adapter on the t-case I can only have like 5 inches total, and the spacer is 1-3/4 thick

 

[1987 GMC Jimmy]

Thanks for the info. I wish I could find just the adapter, you can make the tail shaft work if I remember right. We used to cut like a 1 1/2 off but I couldn't remember wether it was the 6 or 9 inch housing. Older is better, I'm layed off and also have some health issues, so I sold my 07 1500 hd and bought this truck and paid off some bills. I love these old trucks anyway. I got a 72 chevelle that I pay 68 cents in taxes on a yr, antique tags, so I spent the $100 to put them on this truck. Taxes and insurance on the 07 was crazy. I got to get this thing going, I'm driving my old work car right now. Anyone out there with just the adapter or know where I can buy it separate? Great site by the way.

Very nice car, indeed. I would love to see pictures. That year for Chevrolet was definitely the swan song of the American muscle car so you should be very proud you have one. People give the Laguna style Chevelles a hard time in terms of desirability and collectability, I think, but they were good cars and not bad looking - just made for a different buyer in a changing market with changing regulations and insurance constraints. It's just hard to live up to the expectations set by the 70-72's, especially, and preceding year models, too.

 

[84chevk10]

Check and see if you got one, I've got the 208 case, thanks.

 

[84chevk10]

Trying to post pics.

 

[84chevk10]

2 upside down, at least I got them to post.

 

[1987 GMC Jimmy]

I tried to look at your header pattern to see what you had in there, but I couldn't fully tell. It looks metacentric so I'm guessing you have somewhere between a 350 and a 400? Either way, very very nice. That was one of my dream cars when I was a kid. Maybe someday I'll find one in need of saving.

 

[84chevk10]

434, super victor, QF 850 Q series, Bullut solid roller, 658 lift, Motown block with all MSD ignition, Dart 230 heads fully ported and Hooker 1 3/4 headers. I bought it after I quit drag racing, 30 yrs, took the block, heads and intake in on trade for my 582 BBC out of my dragster, It run 4,50 in the 1/8 at a 150 mph.

 

[1987 GMC Jimmy]

Wow. Hell of a machine you got there, buddy.

 

[74 Shortbed]

Sweet ride for sure.