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SBC to 4-speed auto to passenger drop t-case

mark

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OK, so my father-in-law has a Willys pick-up. We convinced him to buy it a few years back from the neighbor of his mother who had it in the garage in trade for his mothers Saturn sedan (yes, pretty sure we got the better deal). But he needed a basic car that he could drive rather than his old willies hot-rod languishing in the garage.

It was an older "hot rod", "street rod" conversion/custom job. From what I've examined so far is seems the PO did a pretty decent job, although I suspect it was done in the late 70's or 80's, maybe even early 90's. Decent but older paint-job, big wide bias street tires (which screams 70's hold out), power steering, GM column, white-spokes and a 50's Chevy step side bed. Over all the work looks pretty good and its a cool truck (which is why we encouraged him to do the trade). Got what looks like and we were told early Scout 80/800 axles underneath (closed knuckle, drum brake :puke:) Small Block Chev, some sort of old, clunky 4-speed (or might be a 3-speed, we haven't played with it that much lately) coupled to a passenger drop twin-stick t-case (haven't crawled underneath but I suspect Dana 18 or maybe a D20). It also runs like crap as the carb is gummed up with old fuel (been sitting for many years before we got it, then probably 4 years sitting in my FIL's garage collecting dust).

So after all that, if I have any hope of my FIL driving it like he should, we probably need to loose the stick and put in a nice auto. We are also talking fuel injection or propane as it will not get driven much (propane's a good choice for that) or far when it is driven.

So, I need some recommendations on a good, easy-to-swap in (so probably stand-alone) 4-speed auto, and then a passenger drop t-case to go with it. Simple is the name of the game on this one, so probably an early 700R4? But which one. And the only t-case I can think that would be the simplest adaption would be a '88-91 suburban/blazer NP241 which aren't all that common and beefier than we need. Any other options? If possible we want to avoid $$ adapters and it would be nice to be able to pick everything up of CL or similar for reasonable prices.

Also considering swapping in a drivers drop front axle, as loosing the closed knuckle and the drum brakes will also be a priority. Also haven't figured out if the truck is going up or down. I.e. nice 4x4 looking Willies (chrome rims, 31-ish BFG AT's), or down (drop it down a little more, nice rims, street tires). This will NOT be an off-road machine. Probably doesn't even need to be 4wd anymore but unless I cut the frame and did a street-rod IFS it wouldn't be right to loose the t-case and front shaft.


So open advice. I'll try to get some pictures in the next couple days. Should have taken some yesterday when we had it out of he garage for the first time in probably 3 years. (I'm doing some remodel work on the house, and need the garage space, so Willys will now live in a Costco Tent in the back yard for the next couple months). If you had what I described above, what route would you go.
 
After a little web searching, its a 50's model, but I don't remember if it had 3 bars in the grill or 5 (thinking 3, so later 50's).

Might also be the original t-90 3-speed and D18 adapted to the SBC. I'll have to look next time I'm there. Either way its time to modernize it.
 
i would go with a 700-208 combo...they can be found in the blazer/burb/truck..they were used from 1981-1990 in the blazers and burbs..1991 and newer were the np241..pickups had them from 1981-1987.. the 700r4 that we build at strange are wired so you just hook up key on power to 1 wire,make sure the TV cable is adjusted correctly and down the road you go..it goes into lockup after 4th gear..
 
If you go with a drivers drop front axle, look for a S-10/15 with a 4.3. They came with 700R4 with a driver side NP231.
 
When you start looking at price/performance/headache as a package it is almost impossible to beat a 5.3/4l60 setup. If you are swapping axles anyway just go drivers drop and you can use the chevy t-case too.
 
When you start looking at price/performance/headache as a package it is almost impossible to beat a 5.3/4l60 setup. If you are swapping axles anyway just go drivers drop and you can use the chevy t-case too.

What Ben said. It is just stupid the amount of tech/support and parts that are available for the 5.3/4l60 combo. I was chatting with another fellow about this a couple weeks ago and how they are the new 4.3/700.

So much is out there for support of them.

Post a pic or 3 of this pile Mark!
 
Took some pictures today. I'll post some more later.

T-90 tranny (assume) bolted to a D18 just as I suspected. After some web searching I think its the original tranny/t-case adapted to the Chevy motor. Clean install actually.

There is some interesting stuff, found a couple cracks in the frame that were welded up. Some of it looks a little sketch but its not, just old skool. This is thing was defiantly put together some time ago and just the expected level of fabrication now is so much more advanced. Should be a fun project.


The LS combo has crossed the mind, the power in this thing would be loads of fun, even a 4.8 would be more than you'd need. Food for thought. However for simplicity, it might just get a TH350. They are a dime a dozen, would bolt up and very adaptable for cheap. OD would be nice, but drivable with minimal work (for now) is appealing as well, since I'll probably be the one wrenching on it and I have enough of my own projects.

Might just leave the t-90 for a little while, but the shifter is WAY too short and actually crashes with the twinsticks... might be time to bust out the welder....

I think you can see why I'm torn between going 'up' or 'down' with it.
 
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It just doesn't make any sense to use a th350 with a 4.8 or 5.3. You're already doing the wiring and have the PCM for the 4l60 to work.
 
i would go with a 700-208 combo...they can be found in the blazer/burb/truck..they were used from 1981-1990 in the blazers and burbs..1991 and newer were the np241..pickups had them from 1981-1987.. the 700r4 that we build at strange are wired so you just hook up key on power to 1 wire,make sure the TV cable is adjusted correctly and down the road you go..it goes into lockup after 4th gear..

This for easy peasy....:awesomework:
 
It just doesn't make any sense to use a th350 with a 4.8 or 5.3. You're already doing the wiring and have the PCM for the 4l60 to work.
You missed the point Ben. I would put a TH350 in it to loose the t-90 yet keep the 350 that is already in it. Like I said, that would be the simplest and cheapest way to loose the stick and get the truck more drivable. Nothing wrong with the motor thats in there other than a POS carb. Fastest fix there might be to just go down auto parts store and buy an off-the-shelf 4-bbl and bolt it on.

the LS/4l60 is definitely something to consider in the future. Going to have to look into that. Might seriously conciser the swap instead of investing in any sort of efi for whats in there right now.
 
i would go with a 700-208 combo...they can be found in the blazer/burb/truck..they were used from 1981-1990 in the blazers and burbs..1991 and newer were the np241..pickups had them from 1981-1987.. the 700r4 that we build at strange are wired so you just hook up key on power to 1 wire,make sure the TV cable is adjusted correctly and down the road you go..it goes into lockup after 4th gear..

I thought the blazer/burb/trucks that kept the square body style after '88 only had the 241 and that was the only passenger drop version of the "new" cases (after the 203 and 205). Did the 208 come in passenger drop before the body style change?

What year did they start putting 700's in the solid axle half tons? That might be an easy way to go. Are the early ones a piece of junk? What years to look for and what to avoid?
 
Any 700R4 once built will be more than ample to handle what you're after Mark...Biggest key is to look for a 'K' case...the NP208 came in quite a few yrs of the square body chevs...I believe from 81-87 p/u.
 
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