A Real Stumper -for 4th gen -miesters out there!

[57chevy]

OK, so I'm new here, been reading this or that and the mifbody.com site is up to speed on what we are doing compared to the rest of the fbody forums we've visited.

We've got a stumper on our latest project a 99 V6 being changed over to a V8 using a LT1 V8 from a totalled 94 25th anniversery TA.

The 99 had a blown V6, which we purchased for a grand. The odd part is about the car is the rear end. The rear wheel sets back very close to the rear bumper cover. There is NO damage to the 99 car, but the clearance at the rear wheel is less than an inch from the rear bumper cover to the stock size tire..

Swapping the 94 rear end into the 99 resulted in the rear end being even closer to the the rear bumper cover than before. At least four inches at the rocker front side but less than an inch at the rear.

Control arms are aftermarket, but in good shape, haven't measured the wheelbase as yet.

My question is -has anybody seen this in any other firebirds out there? No damage to the chassis, both stock and aftermarket rear control arms -and we've still got one odd ball looking car on our hands!

Anyone have ane experience with something like this?

Thanks in advance for any input on this!

57Chevy

[sman]

I have NEVER herd of this, sounds like something is seriously whacked.

[Phantom409]

This is weird???

Why go LT-1 into an LS car??

What K-Memeber did they use?

Do you have a link so we can see what has been done, it might help.

[1BADAIR]

pics

[Phantom409]

Ya, we need a visual

[steddy]

If it were lowered, I believe it would send the rear wheels back. I'd put an adjustable panhard bar in there and bring the wheels further forward, or, bring it back to stock height.

[2002Z4CSS]

Never heard of anything like this before. I would think it has something to do with the after market control arms.

[meissen]

If it were lowered, I believe it would send the rear wheels back. I'd put an adjustable panhard bar in there and bring the wheels further forward, or, bring it back to stock height.

Panhard bar centers the rear end front left to right so the pumpkin is horizontally centered in the vehicle.

I would think it has something to do with the after market control arms.

Bingo. Our stock rear lower control arms are about 19.5" if my memory serves correctly. My dad might remember better than I do, his username on here is Plum Nuts. I'd start by measuring from bolt hole to bolt hole on those aftermarket rear lower control arms (LCAs) and see how far away from 19.5" they are. We still have my v6 rear end sitting at home, so sometime tonight if I remember I'll measure our LCAs again bolt hole to bolt hole and let you know what the stock length is.

The placement of your tire front to back in the rear wheel well is directly resulting from the length of your rear LCAs and where they bolt to the rear end (IE: If they put a relocation bracket on). If you had the rear of the car on jack stands so the rear tires were hanging in air, if you remove the lower control arms I'd reckon they will center themselves real quick.

[57chevy]

A Real Stumper -for 4th gen -miesters out there! Pics added!

Thanks for the input on this!

The 99 had the stock lower control arms on it, had no mods that we could see a ladies car when they lost the motor, I did notice the wheel not being centered under the wheel tub when we bought the car but, I chalked up to worn control arm bushings at the time.

The donor car was wrecked in the rear, picked it up for 1200 since it had all the parts needed to do a motor change into the 99.

We've just started the change over the last couple weeks, (that's how we found the mifbody.com site reading about the engine swaps), yesterday we swapped out the rear ends. The aftermarket control arms on the 94 are from metcomotorsports.com Even though the 94 was hit in the back, in the photos you can see a reasonable distance between the tire and the rocker panel in the photo. Both the original control arms and the aftermarket appeared to be the same, laying on the ground side by side, although we haven't measured anything yet.

We also have a 98 WS6 setting in the garage and eyeballing it we've got about two inches at the rear gap and about three inches at the front. The 98 is a near perfect car that sees about 300 miles a year, so we've got a good standard car to go by.

When we hung the WS6 body parts on the 99 car we inspected everything on the body and control arm mounts, the car has not been wrecked or damaged. The mounting tabs at the front of the control arms hasn't been modified, looks completely stock. All these cars are Florida cars and do not have a spot of rust anywhere.

This thing has really got us stumped! Any help is greatly appreciated!

Pics: Silver 99 taken this am -the wrecked 94 setting where it was when we purchased it.

Chevy

[sman]

Whoa, that is weird?! Ok, different mounts on the rear end? Torque arm loose causing the rear to rotate down and in turn push it backwards?

Thats all I got. I really cant think of what else it could be if the mounts are factory and not messed up on the car. Unless the whole car is tweaked, which you said it wasnt in an accident so idk.

[LSxDreamer]

I agree with spencer, if the torque arm is not on right or isn't bolted in on each end then the rear would be able to roll backwards since there is nothing keeping it forward.

[meissen]

Observation, and this is just observing the two pictures and nothing about the technical specs - in the picture of the 94, the calipers are facing the rear of the car. On the 99, the calipers are facing the front of the car. Did you swap the calipers over or is this all the same?

Is the engine and/or torque arm installed already? Like they said, it could cause the rear end to roll but at the same time I'm having a hard time picturing the rolling of the rear end causing it to move backwards.

What are the shocks and springs that you're using? Stock spring height or lowering springs?

[Phantom409]

Good catch B

Looks like you guys put the caliper mounting brackets on wrong or the rear is 180 in the car.

[sman]

Thats weird, how is it possible? The whole rear would have to be backwards, but then there would be nothing to connect the DS to.

Good catch B, that is funky?!!?

[Phantom409]

I was just saying that would be one of 2 ways it could happen.
If you did it would move your springs 4" or more but it looks more like they mounted the brackets wrong.