So here's the deal guys 89 RS V8 Vortec TBI just finished the engine/ trans swap last April now its time to rebuild the front end. Already ordered brakes all the way around and I have a used spindle to replace my bent passenger side spindle.

Question is, regarding front springs, Moog lists about 5. When searching for the RS model I see the 5610s are the heavy duty with 424 lb load. However when I search for the iroc springs they pull up the 5622 springs with 748 lb. Which should I go with? I assume IROC springs will work?

Also any other suggestions? Doing the centerlink, tie rods, ball joints while I'm in there. Rear springs are also needed as I'm bottoming out everywhere.

 

Yes the IROC springs will work in the RS. RS & IROC are basically just sticker packages from the point of view of the suspension; don't affect the "behavior" of the springs. Main difference is, the OWNER EXPECTATIONS of the people who bought each sticker package, which in turn, affect the choice of suspension optimization.

Same as Camaro/Firebird. Might want to scope out listings for the various Firebird trim levels, as well as Camaro; since the 2 brand names are just minor detail variations in a little bit of the tinfoil on top, and of course, the stickers.

That said, the 5662 and 5664 are the ones for people who want handling; the RS (or base Firebird) variants are for people who want image and comfort but aren't hardcore like most of us here. I think you'll like 5662 better than the others.

CC635 or 5665 for the rear at the same time, as well as all new shocks & struts, front control arm bushings, new rear control arms (don't bother putting bushings in the old ones), and probably strut mounts.

 

Excellent response. Struts and mounts were done in 09 and about 25k miles but may be time. I notice I get a decent amount of front end float at highway speed, not strut blown float though. Also have the wheel jerked from me on pavement changes with about 11-1 on the steering clock being dead zone play.

Planned on doing everything front end except for the LCA bushings. Those seem like a PITA to replace.

So which is the better spring the 5662 or the 5664? I'm kind of iffy on it getting stiffer than it is now. Right now when I hit rumble strips the whole car thunders

 

You'll find that with new rubber (or poly) everywhere and new shocks & struts, the road shock transmission to the chassis is GREATLY reduced.

Wouldn't hurt to replace every sway bar rubber with poly. IMO one of the HHUUUUUJJJJJJJEST bang for the buck improvements you can make.

 

Easy there high roller, I'm doing this on a budget. One end of the car at a time haha.

So two questions for you which iroc spring is the better? The 62 or the 64? Also any idea the sway bar size on this beast for bushing ordering?

 

Both part #s are equally "good"; it's a question of matching your expectations.

The 5664 is the stiffest one Moog makes for our cars.

Most people go with the 5662.

Sway bars will be small; probably 32/21. Use a Crescent wrench and a measuring thing of some sort. Measure right next to the bushing.

All of the sway bar bushings and end links, the whole car, is probably less than $50.

I don't think you'll be happy swapping only front springs. As cheeeeeeep as rear ones are, no sense having a car with sagging weeeeeek rears and nice new fronts. You'll see.

 

To expand on Sofa's post:

The Moog 5660,5662 and 5664 are designed to all have an installed spring height of 10 3/4"

The 5660's need 1538# pounds placed on them to arrive at that height
5662's need 1690#
5664's need 1863#

 

And keep in mind that those #s are the compression force on the spring, not the car weight. In these cars the car has about a 2 or 2½:1 lever arm on the front springs, meaning, the 800 lbs or so of car weight on each front corner, puts something more like 1800 lbs on the spring; and conversely, 1" of change in spring length, corresponds to 2 - 2½" of change in car height.

 

Well guys, I pulled the trigger last night. Parts List is below. Also bought ACdelco rotors, drums, pads, and shoes from amazon to go with the parts below. Was very expensive. To save on labor I'm going to install myself with the exception of ball joints and LCABs

 

I see your 5662s there RS. That's quite a list.

Did you order new rear springs as well? I don't think you want to significantly increase the front spring rate / roll rate without changing the rear to match / balance it?

 

No rears yet buddy. Have a budget to follow.


All parts are here. Looking to install soon. Any special tips out there? Machine shop wants 90 to replace bushings and ball joints

 

Minor update. Ball joints were completely loose, LCARBs were cracked, and Tie rod ends won't hold themselves. Just got back the LCAS

 

New goodies

 

Found this thread with the Search function - far better than starting a new one huh?

So the Moog 5662 would be a direct replacement for the front springs on an 87 IROC regardless of engine?

I'm not sure what's in there now but the car has a distinctive Nose Up stance.

 

You'll be fine as long as it's a V8