badtexasZ28

I have looked around through a couple of forums and havent been able to find my answer....

I have a 1997 Astro van that is AWD and want to use a LM7 from a 2002 Tahoe as a donor engine, will the transmission in the van work and if so what do I need to make it work?

Thanks!

Also if anyone has a service manual for a 2002 Tahoe with a LM7 or has an online source let me know, I could use it to help with the wiring.

Jimbo1367

I believe that is a th700R4. Yes it will work for a little while.(until it blows up) I believe you will need this flexplate adapter. Do a search You will need adapter plates for the engine. A ECM and harness ( I am choosing www.speartech.com ) and a cable TB to work with the th700r4

Jimbo1367

the flexplate adapter is listed in this thread. https://ls1tech.com/forums/conversio...-question.html

Pocket

iTrader: (22)

97 trucks used the later 4L60E. The electrical is compatible, it will bolt up, but you need the adapter flange listed above. Beyond that you should be set

For wiring do a search on here for a specific schematic, check out LT1swap.com and Ive made several posts here
http://www.thirdgen.org/techboard/po...009-post4.html

Go for it

badtexasZ28

Thanks for the info, so the adapter is a GM part? Thats convenient... Looks like all I will need is to figure out the wiring and mod the oil pan to fit and work with the AWD system.

Pocket

iTrader: (22)

Wiring is the same. Connector too

AWD shouldnt be any different as far as wiring. 4WD will with the electric switch for 2WD to 4WD

badtexasZ28

What do you mean wiring is the same?

Jim85IROC

iTrader: (6)

The wiring may not be as difficult as you think. Some of the later vans that used the Vortec SBC motor used the same ECM as the LS1 cars, so if you can nab one of those harnesses, your modifications may not be as substantial as if you start with your existing harness.

Pocket

iTrader: (22)

Im saying the pinout, connector on the trans, and general function is identical for the older style trans as the LSx. So plug the 4L60E connector that comes with the new LSx harness right in there and go for it

The only thing to watch for it a 4L80E harness as the connector pinout is different. It is the same connector body as the 4L60E and can be repinned to match. Just be aware of the difference

badtexasZ28

My harness is from the LM7 that was pulled from the Tahoe along with the computer. Did the Tahoe's have a 4L80e or 4L60e tranny? Also when did they start putting the "Vortec" 4.3s in the Astro vans instead of the regular 4.3s?

Pocket

iTrader: (22)

Tahoes got both 60s and 80s. Most likely it was a 60 behind the LM7

See if your colors match up with the pin assignments on the trans connector. The low ref wire can be blk or ppl



Vortec V6's came out in the early 90's. Some of the 2.8's even got the title. They really didnt become standard until the intakes followed the V8 vortec pattern with vertical bolts in the corners, raised runners etc. By regular 4.3 Im guessing you mean the TBI version which was the last incarnation before the swap to vortec. Those phased out completely in 95 IIRC

badtexasZ28

Sweet thanks Pocket, thats what I meant about the 4.3s when they lost the TBI. Can I use the ECU from the LM7 removal or can I reflash the stock Astro ECU?

Pocket

iTrader: (22)

97 PCM wont run the LM7. Use the tahoe unit or another compatible with your harness

badtexasZ28

Thats what I thought. Now I wish I had a copy of LS1edit or HPtuners for the programming after i get it installed.

I wonder how long the AWD will last behind a mild cammed LM7?

N21923

iTrader: (8)

In 97 (maybe 96), same as when they switched in the S10s

Not long. The AWD transfer case isn't very impressive. To keep the AWD, you'll need to cut and paste your oil pan.

Come down this way if you wanna check out one. I was the first person over at astrosafari.com to put a GenIII SBC into an Astro, which turns into the Fastro. Since the swap wasn't documented, it was a major PITA.

http://www.youtube.com/watch?v=FlIvn19xgfQ

badtexasZ28

Where is "down this way"? I would like to check it out.

N21923

iTrader: (8)

Oh, sorry, I thought my location was in my profile.

Greenville, SC

Kenova

iTrader: (4)

The full sized vans were/are available with AWD. They also use the 4L80e trans.
I'm sure this combo would be stronger than what you have now. Something to think about down the road.

Ken

badtexasZ28

Well Im down in Tampa, FL and was hoping you were on the way home since I am leaving tomorrow. Maybe when I get closer I will come down and see your swap