Can You ID a G Body 8.5 By Upper Mounts?

[jrm81bu]

My original question might not have been worded very well. I'm looking to buy a rear for my car and the guy sent me the picture that I attached above. He is claiming that it's from a mid 80's T Type but I was hoping to get confirmation from someone here. I was hoping someone might be able to look at it and say "yes, that right ear is angled differently than the left and they are mounted higher on the center section, so , yes that looks like it is from a G Body." I don't really know if someone would be able to tell that from a picture, but that's what I wanted to find out.

Thanks,
Troy

It's gonna be pretty hard to tell from a pic.

If the mounts were in different locations wouldn't you need different trailing arms or something. From what i was always told the 8.5 is a direct bolt in swap for the 7.5 so thats why i believe everything is in the same location but

you are correct... the 8.5 is a direct swap from a 7.5... as long as they are both from G-bodies...

but other cars used 7.5s and 8.5s too... so that's where it gets tricky. Cuz other vehicles like A and B bodies had different ears and spring mount locations than our Gbodies.

That's why I said the larger measurment came from the B-body 8.5 I had.

This is a curious topic.(in a good way) I was told by someone that the 8.5 axle from the Astro van / Venture van was a "bolt in" for our G bodies as well. Since I have a 8.5 that no one can figure out where it came from(correct in every dimension/measurment I could find) I'm interested in any extra info that pops up.

Not a chance. The Astro uses a leaf spring Rear suspension, not to mention that the majority of them had 7.5's anyway. At least all the ones I've owned were 7.5's. And the Venture van is front wheel drive.

 

[Kris_84elky]

Idk if theres any way you could tell that's a G-body rear just by looking at that photo. If I were you I would ask for the codes off of the axle housing and axle tubes. Also you could measure the width of your rear and where the brackets are located and compare the two. But any codes on the rear end should tell you what it is out of.

 

[art]

Not a chance. The Astro uses a leaf spring Rear suspension, not to mention that the majority of them had 7.5's anyway. At least all the ones I've owned were 7.5's. And the Venture van is front wheel drive.

That's what I thought. The "ones to look for" were the awd versions so I figured something was up. Thanks for clearing that up. Misinformation among people polishing their own apple to seem "knowledgeable", really bugs me.

 

[tdvick]

I tried the code route in another post, "Decode the Code". He told me 6TJ. No match there unless it was misread and was really GTJ. I thought the picture was worth a shot. Some guys can really spot the details.

 

[jrm81bu]

Not a chance. The Astro uses a leaf spring Rear suspension, not to mention that the majority of them had 7.5's anyway. At least all the ones I've owned were 7.5's. And the Venture van is front wheel drive.

That's what I thought. The "ones to look for" were the awd versions so I figured something was up. Thanks for clearing that up. Misinformation among people polishing their own apple to seem "knowledgeable", really bugs me.

Ha, my 96' AWD still has the 7.5 in it. Besides just being leaf spring rules them out completely, just like the s10's.

 

[85GPLef41]

I googled "6TJ 8.5 rear" and it went to this web link: http://gnttype.org/forums/archive/index ... 12481.html

and found the one code you posted it is listed... that rear looks extremely like both of mine which one is a 3TP off a 87 GN the other is off a 84-85 442 with 3.73 ..... Then again i'm also looking at pics i took. but i would assume its a g body 8.5 and the only way to find out is to measure it and make sure. How much they asking for it?

Although not listed specifically on the SPID label here are the most common rear axle codes for the TR.
1984 8.5" 3.42 Ratio
GTE
GTP(Posi)
6TJ

1985 8.5" 3.42 Ratio
8TJ
8TP(Posi)

1986 8.5" 3.42 Ratio
2TJ
8TP(Posi)

1987 8.5" 3.42 Ratio
2TJ
3TJ
2TP(Posi)
3TP(Posi)

 

[tdvick]

$500, complete with aluminum drums. I would have to get it shipped so that might be the deal breaker for me. It's located in Missouri.

 

[tdvick]

Thanks for the input guys. I did end up buying this rear. Just picked it up yesterday. I had it delivered from Missouri up to Minneapolis. It is a 6TJ rear out of an '84 T Type. Now I just need to find a posi case...

Troy

 

[85GPLef41]

Thanks for the input guys. I did end up buying this rear. Just picked it up yesterday. I had it delivered from Missouri up to Minneapolis. It is a 6TJ rear out of an '84 T Type. Now I just need to find a posi case...

Troy

Nice! 8) I am thinking of picking up a Detroit TrueTrac for my open 8.5 but upgrading the axles to moser 30 spline and a girdle just to make it look tough along with a complete rebuild. Unless something cheap comes up.....

 

[79loserbluebu]

I don't think the 7.5's ever came with aluminum drums.