Now....I understand 4th gens have wider rears....

But from my understanding....LT=1.75" wider, LS=.75" wider...Correct?

 

I dont know what you mean by LT and LS, but when I swapped my 4th gen rear in out of a 95 LT1 Camaro, it was a full 4 inches wider than the 9bolt that was in the car before.

 

LT1 & LS1....It is my understanding the when the LS1 came out, the rear end was narrowed a bit.

And by the #s I posted, I meant per side, not total....Sorry.

 

Just curious, how did you get your numbers? I dont see why they would have made the rear ends wider for the LT1. But then again Ive never measured the LS1 rear. My measurements may be off, I just took em really quick to see the difference before I put the LT1 rear in.

 

Well, it's always been common knowledge that the 4th gen rears are wider, hence the need for adapter/spacers to run 4th gen wheels, or just run a 4th gen rear, to run 4th gen wheels & no adapter/spacer needed.....To run them on a 3rd gen.

But researching a bit, I find things that seem to hint that the LS1 cars rears were narrower, just not all the way back down to the 3rd gen width.

 

I also have hears the ls1 rears are a bit smaller, but it was my understanding it was 1/4 to 1/2 an inch on each side.

 

I never got Reply Notice. Not unusual TGO doesn't always send out notices....

OK...1/4" to 1/2".....Anybody KNOW? Have access to both rears to measure?

Anybody here wanna measure their 4th gen rears & report the results?

 

I never seen any difference, they all should be 1.75 each side.

 

When I put an LS1 rear in my '88 T/A I measured them and came up with 1 5/8" wider on each side.

AFAIK, LT1 and LS1 are same width.

https://www.thirdgen.org/forums/post...048-post9.html

In that bottom picture, it is not the LT1 rear that is wider, its the front wheel with zero offset being used on the rear, which makes the wheel stick out further.
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And I think you should stop replying to everyone else's threads with bad information regarding LT1 and LS1 rears

 

The LT1 styles rears and the LS1 rears are the same width. I have NEVER heard anyone say they were different.

If you like, i can measure my car(lt1 rear) ID tire to tire and do the same on an LS1 rear. I already know the answer, but i will do that if you wish.

If the rear had been narrowed, the LS1 cars would need a different offset wheel i would imagine, which is not the case.

 

Far as I know they're the same width. I could see where you could find an 1/8" over all variation tire to tire based on different aftermarket rotors being made to different standards

 

I was told they are slightly different. It appeared to me that my LS rear end was about 1.8 inch wider per side... or around 3.625 inches longer overall than stock thirdgen 9 bolt

LT rears i've heard and was told by others that they are slightly longer overall at almost 2inches per side, or about 4inch overall. not much difference but there is some

I think the difference is due to the brake mounting differences...possible backing plate differences i'm not sure

 

Don't know about Lt rears, but I just happen to have an ls1 and 92 drum rear in the garage sitting next to each other if the pic helps...and by no means is this a scientific accurate measurement...tape measure and eyeball method

 

I have measured both LS1 and LT1 rears with out tires and they are the same,could it be that some people measure them with the tires mounted and that is why they get different lengths.

 

I have also heard there is a difference in the lt1 vs. ls1 rears. The lt1 is supposed to be wider. I will be upset that I passed on a few lt1 rears if that is not the case. I read it somewhere on this board.

 

What does the LS1 rear measure with the discs in it? I see the 65", but that doesn't tell us where the wheel sits. Only where the rotor sits.

See, my issue is this....
I have the correct 3rd gen offset ROH Snyper wheels on my car.
They only sit in by about 3/4", from the fender lip & I don't want them sticking WAY out. Lined up or maybe 1/4" out, fine..
They are 17' x 9", with 285s on the rear. My 9-bolt works great. Perfect posi, but SMALL discs. 10.75"....
In 89 they went to 11.75"....LS1 would be 12.75", IIRC. That's a 2" increase in disc size for me.

I almost wanna put my crosslaces back on, to hide my small rotors. With the Snypers, they are very visible.

So....I wanna swap in a 4th gen rear for the bigger discs, not if it pushes the tires way out past the fenders.

 

I think if you do a 4thgen swap you are going to have to get new rear wheels. I would just get a big brake kit for the rear you already have. I dont have wheels for my 85 T/A yet so I'm swapping to a ls1 rear first.

 

Getting new wheels isn't acceptable to me. There is another option, if the LT1 rears are wider than LS rears, but that option requires more $ which I don't have....For right now.

Ad...Why spend $700 on brakes alone, when I can buy a stronger, complete rear end for half that?

 

The LS1 and LT1 rears are EXACTLY the same width. No question about it at all.

I can't see why you say $700 for a brake kit. I picked up a LS1 rear with disks for $275 off of Craig's List. Pulled the disks, then sold the zexel posi for $200. Put $60 more into the swap for braided brake lines, and for $135 total I have LS1 rear disks for my 3rd gen rear.

 

I simply can't put 4th gen 10 bolt discs on my 9-bolt.

 

Didn't know it was a 9 bolt. Didn't see anywhere in your posts telling us that.

 

Well....GTAs came stock with "9-bolts". My sig pic clearly says GTA.

And the left side under my avatar. Dana M78 (the real name of a 9-bolt)

 

Oh yeah....No offense, but at this point, I'll believe it when I see it.

Nobody seems to KNOW, as in....They've measured themselves or know someone who has.

People keep saying they KNOW, yet when asked HOW they know..."I just know." or o more response...

 

I've seen it, had LS1 and an LT1 sitting here side by side. Axles are direct interchange. But honestly..................I don't care to try and help you any further.

 

Why? Because I won't take YOUR word as gospel, when others say different?

"alloy says they are the same...That's all the proof I need." Whatever.....

 

No, I could care less if you take my word for it or not. It's your attitude towards those who go out of their way to try and help you.

 

Let's see...I start off by saying "NO OFFENSE"...You've"helped me" in ONE POST..YOUR post contradicts other posts in this thread....

Now..I'm supposed to disregard everybody else's opinions and just believe YOURS?

Yeah...I'm gonna trust a person who hides behind his SCREEN name. Who, quite frankly....a new member & can't even use his real name. Yeah...real trustworthy....

 

New member???


Join Date: Jun 2002
Location: washington state
Posts: 940

 

Compared to me...Yeah...New member. I was in the 3rd gen community online, before the 3rd gen community became TGO.

Join Date: Jul 1999
Location: Austin, TX
Posts: 4,309

In any case...Stop littering my thread.

Just because I didn't believe YOUR word, when it contradicts others, doesn't give you a right to whine. I guess if I believed you, the others get to whine?

 

Do you guy's realize that argueing about 1/8" or so on a C-clip rear is pointless on the web. Depending on how the axles are sitting at any given time you could get different measurements. Aftermarket axles are identical for all 93-2002 camaros. You can then determine that the rear axles are identical because the centersections are the same. If you really wanted to know if there is a difference then measure from the insides of the LCA mounts. Also membership length and post numbers can have everything or nothing to do with the validity of a member's information. A GM master tech could join today and know more about these cars then any of us ever will or a twelve year old could put up thousands of posts of nonsensical garbage.

 

You are absolutely correct WIll36. I've only owned my third gen for 22 years now, and I'm learning new things about it every day.

 

Ahem, he said it in post #16, 5 posts above yours.

Yes you can put 4th gen 10-bolt disc brakes on a 9-bolt. Both my car and my father's car have LS1 rear brakes on our 9-bolts. But we started with the '89 9-bolts that already had the larger 89-97 rear brakes. I dont know how much different the 82-88 rear brakes are that complicate the swap. Its not a direct bolt-on and it takes a little fabrication, but it can be done.

That said, I have no idea exactly how much wider a 4th gen LT1 or LS1 rear end is over our thirdgens.

 

What kinda fabbing you talking about? Doing that would eliminate any possibility of my wheels sticking out...

 

The holes need to be alongated, the two top ones "up" the two bottom ones slightly "down and out". (make a pattern off the old backing plates)
Then a spacer made to make up the difference in thickness of the backing plates.

See picture

 

Interesting......

So....I'm guessing then, that the splines get less engagement & the axle to housing tubes might need to be longer bolts? Or is there enough threads to full engage the axle?

 

The axle remains in the same location, the plate that holds the bearing and seal in is held out by the thicker backing plate, hence the spacer.

The 9-bolt backing plate is about a 1/4" thick the 4th gen one is about 9/16th's if you don't put in a spacer the plate won't push the axle in far enough.

Also, there are a couple of ribs on the backing plate that need to be ground down so the plate sits flat.

 

Any place that those spacers? Or would I hafta find a local CNC place to make them?

 

You'll have to have them custom made.

Be sure to measure the thickness of both backing plates and make the spacers the thickness of the difference.

 

I have already put the 4th gen rear on my car so it would be hard for me to measure it now to see what the width is with the discs on. I have some 19x9.5 Ruff racing wheels I put on the rear just to see if they fit, and they fit with no interference, however they were just the rims w/o tires, but it looked like the tires would have made no difference. I don't have any experience with the wheels you want to put on your car but the 19's fit with the ls1 rear, if that helps at all.....and yes I probably qualify as a newbie with my posts...but I like to help if I can...

 

Thanks, but diameter nothing in terms of the fit. And width means little without backspacing (offset). 6" wheels can still out while 10" tuck....Without a backspacing (offset) measurement, nobody can make any judgments.

 

I have stock 1992 rs/z28 wheels on right now and they do stick out further than the old rear, but they do not go past the fender lip. I can take a picture to show you if that would help you, other than that I guess this is beyond my expertise...what little there is....sorry I couldn't be more help...

 

Thanks. But a local guy here has stock 16" rears on his 91. Not sure which year his rear is, I just know it's a 4th gem rear.

Maybe one day I'll be able to get the year of it & get him to measure it.

 

OK, I have some info on the lt-1 rear vs. the thirdgen rear; A friend (sfeeney) just did a lt-1 swap and has discovered that it is at least 1 1/4" PER SIDE (At least 2.5" overall) Longer. The factory 16" wheels still fit without hitting the fender lip but they almost touch. I will try to get pics of this on sat, if I see the car at his house. The factory rear was a 10 bolt disc, the Lt-1 rear, I think came out of a 97 z-28. Sorry to revive an old thread, but I thought it would be good info for anyone interested in doing the swap. I am still trying to get info on the LS-1 rear.

 

Yeah...Like this blue Camaro parked next to my GTA.
4th gen rear, stock 3rd gen rear 16" wheels.

 

Yep! I guess its fine as long as you use the stock wheel/tire combo, but if you like to push the envelope like I do... I am kinda going for the "pro-touring" look on my T/A, so I want as much "Dish" in my wheels as possible. With a wider axle, you would need more backspace, and therefore, Less "dish". (I'm sure theres a better word for it than "Dish", but right now I cant think of it...)

 

I can no longer find my old catalog from Strange engineering, but it had the specs for this thread's original question.