1987 Astro Tiger 2wd To AWD/4x4

[hburge]

Hey guys.

I Understand that there is a lot of information on this forum and others. A lot of the information i have found by spending hrs looking at my screen is on second gen astros. So please forgive me if i have missed a previous post and would greatly appreciate a redirect .

I will start with a breakdown of what im looking for in my rig. I have a 1987 Astro tiger gt 2wd TBi. I live in the mountains and frequent forest service roads in the summer for fishing and camping. I also drive frequently in the snow during the winter season. I dont need a rock crawler but a capable of road machine that doesnt get stuck in sand as i just did at lake powell. I have two weeks left of work and i am going to straight at this project for the next month. I am not a mechanic but i am mechanically inclined and have more experienced people helping.

Finally got my donor astro for my 1987 Astro Tiger 2wd to AWD/4x4 conversion. It is a 1993 Astro with 150k automatic (not sure if its electic or not) with 3.42 gears in it and the CPI engine.

Ive decided im going to take engine (CPI) diff t-case transmission from the donor to put into the 87 tiger.
I would like to get a select trac t case to put in while i have the whole subframe out. I live at Lake Tahoe where i am driving in the snow a good portion of our winter. If you feel the select trac is not necessary let me know.
Im also looking at lifting it and increasing tiresize and regearing of the front and rear diff.

First question. Np242c or np 236 or something else. i understand one is manual and one electric. Is electric doable in these first gen astros?

Second. After doing a bit more research i feel that with the weight i am constantly carrying with the Astro Tiger regearing is necessary especially once it is lifted and larger tires installed. Do you feel 3.73 is enough or should i go for the 4.10s. (thinking 4in lift and 31 by 10.5s) Also this is a vehicle i will be using for extended trips, how much top speed do you lose with regearing if any.

Third. To get this regearing, Should i regear the front and rear diff from the 1993 3.42 front and rear. Or should i just look for front and rear diffs from junk yards?

Fourth. I understand this is under the wrong section of forum but Lift recommendations. I havent seen too much about ball joint spacers and spring spacers. Mostly just subframe spacers ?torsion keys and new leafs.


I will stop at that. I know i have 50 more questions but lets not overload this post more than it already is.
All help is appreciated and i hope i can contribute to this awesome community because Astro Safaris simply just KICK ASS.

[mdmead]

Hey guys.

I Understand that there is a lot of information on this forum and others. A lot of the information i have found by spending hrs looking at my screen is on second gen astros. So please forgive me if i have missed a previous post and would greatly appreciate a redirect .

Welcome!

Finally got my donor astro for my 1987 Astro Tiger 2wd to AWD/4x4 conversion. It is a 1993 Astro with 150k automatic (not sure if its electic or not) with 3.42 gears in it and the CPI engine.

The transfer case is the viscous clutch unit. The best one in my opinion. They are reliable and nearly bulletproof.

I would like to get a select trac t case to put in while i have the whole subframe out. I live at Lake Tahoe where i am driving in the snow a good portion of our winter. If you feel the select trac is not necessary let me know.

I'm not sure you need a 2-speed case given your use. If you plan a lot of really slow going, you'll want it to help your transmission live. They get hot creeping at low speed without low range.

Second. After doing a bit more research i feel that with the weight i am constantly carrying with the Astro Tiger regearing is necessary especially once it is lifted and larger tires installed. Do you feel 3.73 is enough or should i go for the 4.10s. (thinking 4in lift and 31 by 10.5s) Also this is a vehicle i will be using for extended trips, how much top speed do you lose with regearing if any.

I'd go with 4.10 gearing given what you have. 3.42 certainly is a bad choice, and if you increase tire size with the motorhome, I think you'll find the 3.73s aren't very good. Also, 4.10s might allow you to skip the 2-speed t-case too.

Fourth. I understand this is under the wrong section of forum but Lift recommendations. I havent seen too much about ball joint spacers and spring spacers. Mostly just subframe spacers ?torsion keys and new leafs.

The best way to lift in the past (beyond a basic 2" spacer lift) was a weld-in lift using capped steel pipe and reusing your stock mounting bolts. The latest lift method I've seen uses square tubing and gives you the opportunity to slide the front subframe forward a bit to give more tire clearance at the rear of the front fenderwell. This will likely be the route I go when I get around to doing mine. I would skip changing torsion keys or messing with ball joint spacers. For the rear, I'd go with parts from Journey Off-Road, specifically the new rear leaf hangers.

Sorry this response is late in coming. Hope you are finding the info you need in the archives here and elsewhere on the web.

[Captn. Crunch]

Great project-I love those tigers! You will be going from carbed to fi right? If so you will need the ECM included in the swap. The BW4472 tc in the 93 was I tried and true unit but parts are no longer available. The np236 swap is all electric and electronic and I wouldn’t recommend it unless you love wiring and computers and puzzles. The preferred swap lately has been the 231 or the 233. Lots of posts on these including making your own linkage.
As you have a complete doner van, I personally would take both front and rear diffs to an axle shop and have them install Yukon or some other US made 4.10 gear sets. Stay away from imported lower priced gear sets. Don’t skimp on the gear sets. I had an axle shop install Detroit TruTrac Torsen style LSD in the rear and an MFactory Torsen style LSD in the front diff of mine and I’m very pleased. It was pricey but I’m glad I did it. I’m running the twin Torsens in conjunction with the np236 swap so its all computer controlled and idiotproof. Which is a good thing for me.