I am in the process of putting a zexel from SLP in my 87 this weekend, and noticed I've got one blown rear Monroe Formula GP shock. The front struts are good, and since Formula GP's have been discontinued, what shock would be a good match to replace the blown GP's? I'd like it to match the front GP's as close as possible. I've done a search on this forum, and can't really find an answer to my question.

Thanks-Dan

 

Well considering that those were discontinued about 10 years ago, the front ones are probably bad too.... "matching" to them would be the wrong approach.

Just get whatever you want for the rear, and plan on replacing the fronts with the same thing. Put in new rear springs while you're there, they'll fall out while you're doing the shocks, they're exactly zero extra labor.

 

The car sit for a number of years, so there isn't many miles on the shocks. Mostly just age. The fronts seem to be in very good shape. Springs also. I've got measurements on the ride height from when the car was fairly new, and it's within 1/4" of new height. So for now I'll have to wait on the springs. Just blew arond $350 on the zexel and 3.42 gears along with other related parts.

 

just get new rear monroe shocks..

 

formula350-These aren't regular shocks, and Monroe has discontinued them and has no direct replacement currently offered. These are stiff performance shocks and worked very well for autocrossing, and I'm going to be getting back into autocrossing next year in E Street Prepared. That's why I want to match them as close as possible to the front struts. For now I can only replace the rear shocks because I just sunk $350 into the zexel and 3.42's.

Anyway in a couple of hours when I finish getting the rear installed I'll let you know how 3.42's and the zexel work.

 

Well I got the 3.42's and the zexel in yesterday. As expected my speedo is way off, but I'll take care of that later. The 3.42's are quite a change. I haven't gotten on it yet to see how the zexel is since I've got that one blown shock and I don't want to take any chances with it. One thing I did notice that everyone should take note of is that with the zexel you can't check for a posi in the traditional way. If you spin one tire the other goes the oppsoite direction. And I'm told that the 4th gen rears don't have the tag telling you to use posi additive, so I guess you have to take the cover off to check for a zexel posi.

On the shocks I made a lot of calls and the best I could do for replacement shock is Koni's. Got them from shox.com for $200 for the pair with free shipping. Hopefully they will be here on Friday.

 

The GPs are hard to "match"... my little bro used to get them from the Monroe rep where he worked, he had a set on his MC SS; semed to me like they were not much different from a stock shock on long-duration events like going over an e-way bridge with uneven concrete slabs, but on short duration things they were real stiff. The car seemed to ride hard until you got up some speed, then it felt slushy and kind of flopped up and down like a typical land barge. I didn't care too much for them. His also leaked alot; for a couple of years (and a couple of warranty sets of them) at least one of them at all times had a drop of fluid about to drip off. The car would leave 2 or 3 little drips of fluid if he parked it somewhere for a couple of days, one under each wheel. I guess they just didn't work out well, as a product... I wasn't too surprised when Monore turfed them.

Good luck!!! I think you'll like these others alot better.

 

I liked the Formula GP's when they were working good. I was heavily into autocrossing about 10 years ago and with the GP's on the car I won a the local F stock championships several years running, and took a divisional or two also. I'm thinking about getting back into autocrossing again, but this time in E Street Prepared. Prepared allows me more mods to the car, so I can play around making things for the car like a panhard bar, LCA's, and other stuff. (I own a machine shop)

I'll post when I get the Koni's on and let you know what I think of them.