I searched before posting this and didnt find the answer I was looking for.

I have a 350 1989 Iroc Z with 60,000 miles and my fuel pump is going out on me. This weekend we are putting a new fuel pump in it.

Well while I had it torn down for this, I thought about putting some 4th gen rear springs on it. I have a pair of 4th gen rear springs from a 1999 Trans Am with about 40,000 miles.

Will these springs change the ride height and would they be better for my Iroc?

I dont want to put them in and then the car sit lower in the rear than the front.

So can someone answer this for me, please.

 

A lot of the factory springs were pretty close.

FWIW, new take-off TTH fourthgen springs raised my rear ride height a bit (~1") compared to thirdgen NNL's.

Rear springs are easy to change, so why not just try them?

 

Thanks for the info. Just the answer I was looking for.

I'm not sure if I wanta raise it 1" in the rear or not.

 

Just try them, if you raise the body until the rear starts to come up the springs will almost fall out by them selves. Takes me about 10 minutes to swap out a set of rear springs. You dont have to unbolt anything. You may have to play with the spring to get it out though. I have 02 WS6 rear springs on mine without isolators, just rubber hose to keep it from being metal on metal. Sits OK for me right now...............jt

 

Then those are the springs I have then.

Cause 1998 was the only LS1 year they changed the springs on the WS6 cars. They had so many ride complaints that in 1999 - 2002 they just left the stock springs on the car and changed other stuff.

 

I should have pointed out that was a comparison between 15-year old used NNLs, and brand new TTHs...so some of that change may have been that my old springs were already sagged lower than normal.