My Grandson put me onto a company called UMI Performance, who is apparently trying to make it into our market. Here's their info on a complete set of rear arms for A Body cars. The price of $200 for the set of four looks very good. Is anybody familiar with these folks?

This complete kit includes one set of upper control arm replacements and one set of lower control arm replacements. Both sets are constructed of DOM mild steel tubing 1.625" OD x 0.120" wall thickness, 0.250" CNC machined rear housing and feature Energy Suspension® polyurethane bushings and "in car" grease able zerk grease fittings.

Rear control arms are a must upgrade for any GM G-Body. These direct bolt-on replacements minimize wheel hop, improve cornering while lowering tracks ETs and helping track consistency. Control arms come complete with polyurethane bushings, grease fittings and zinc plated steel sleeves.

Installation:
Installs in 2 hours using OEM hardware. All installation instructions included.

Available colors:
Powder-coated Bright Red
Powder-coated Gloss Black

Any rear arms with poly-anything are no good. Not an opinion, this is proven fact and most of the manufacters of these arms know it. Look for arms with spherical bearings or "jonny joints" ala Currie enterprises.

Sounds like a pretty good price. Hopefully the quality is there. Don't worry about using poly bushings. Millions of cars have them. Spherical ends are quite expensive and not really needed for a street car or low budget race car.

Yeah, the Jegster arms with rod ends are real pricey at 159.00 and 169.00/pr :rolleyes:

Any rear arms with poly-anything are no good. Not an opinion, this is proven fact and most of the manufacters of these arms know it. Look for arms with spherical bearings or "jonny joints" ala Currie enterprises. I agree with Dennis... Unless its a drag-race vehicle where you might want to reduce the rear squat under accelaration...

The Poly bushings in the entire rearend setup will bind... Mainly the upper arms... Poly in the lowers is okay.

Spherical ends are quite expensive and not really needed for a street car or low budget race car. The poly bushings are meant to limit deflection of the bushing, but the "bind" caused by the converging link setup in increased with poly bushings, also increasing the suspension stiffness beyond what is needed for good handling and ride comfort. Contrary to popular opinion, stiffer is not always better (or else racecars would have solid suspension).

Basically, the upper arms (because the work at such an extreme angle relative to each other) need some flex (either in the bushings, joints or arms) in order for the suspension to work properly. Poly bushings with boxed upper arms will bind significantly and cause unintended stress on the upper frame cross-member. The spherical joints (Currie and Edelbrock too) help to address (but not totally eliminate) this issue.

Poly in the lower boxed arms is not as bad, because these arms are almost parallel to each other, reducing the bind (although still there).

This is also a big problem with the late-model Mustang's (1980's and 1990's at least) since they feature a similar rear suspension arrangment.

If you really want those boxed uppers from UMI (I haven't heard of them), at least replace the upper arm bushings with rubber (and maybe new rubber in the rearend housing as well)...

66Elky BB, thanks for the lead.
I checked out their site. It's a good price. Unfortunately if you click on the 64-72 product link, it shows you products for 68 to 72 A bodies. I hope they pay better attention to the details of the quality of their products.

I'm also curious about how you mount a sway bar on these units.

Herb, check these out-good deal for 64-67 ebay link (http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=7929227045&category=42609)

www.bmrfabrication.com (http://www.bmrfabrication.com) make some nice pieces. I have the lower control arms.

Denny, Mrgto, THANKS! BUT, you guys have me totally confused now. Rubber vs Poly, rod ends and no bushings vs fixedlength, stock boxed vs tubular. Gee whiz guys, what's the deal?!?

I'm restifying an occasional driver, non-racing, only get on it every-now-and-then CRUISER. It's a 67 Malibu that was trimmed out like an SS (a clone), has a warmed up 400 SB, 4 spd, 10inch open rear. I will put SS frame braces in it, have the frame gavanized (FOFYDYFO lives in my neighborhood)and keep my eyes open for a 12 inch posi rear. I'll also replace the Sag with a Muncie from Wally. All in case I ever want to drop a 454 in it.

What do you reccommend? Stick with stock rear bars and a BIG A_ _ sway bar of buy the e-bay adjustable upper units cuz they may be cheap even though I don't really need adjustables?

I think I now have too much information and don't know what to do with it. :confused:

Herb, I like the adjustable upper for several reasons:
1) you can adjust pinion angle which in a stocker is PROBABLY ok, but you never know.
2) the rod ends eliminate (for the most part) the huge bind that tends to occur in the UCA from the converging design of the suspension
3) they are pretty cheap considering what going price on poly-junk arms are going for.

I'm restifying an occasional driver, non-racing, only get on it every-now-and-then CRUISER...What do you reccommend? Stick with stock rear bars and a BIG A_ _ sway bar or buy the e-bay adjustable upper units cuz they may be cheap even though I don't really need adjustables?Herb, I will concur with what Dennis last said. IMO, IF you want to change the upper arms, then go with arms with the spherical joint (and adjustability).

For a cruiser though, the stock uppers will probably be adequate, with new rubber bushings of course (I'd definitely replace the 37-year-old bushings)... Its when you want to really apply some power with sticky tires (either in launching or handling)... If just cruising, you shouldn't notice a difference that the aftermarket arms would offer... You can always add those arms later if you think you need them (and therefore save your money for other items on your list).

The upper arms will do little to eliminate body roll/sway (which is what the big sway bar will do). There is the exception that the uppers with poly will reduce sway, butthey do it by binding the suspension (not the correct way). Old body bushings and worn front suspension bushings can also greatly affect body-roll...

The SS-braces will not do alot for handling (especially with the other compromises), but they will help strengthen the frame/crossmember/suspension pickup points. A good addition IMO... And the Hotchkis/Edelbrock braces will far exceed the stockers (the thin metal tends to crack, as I have seen on several of my stock sets, and the open channel shape tends to flex more than the tubing).

So for a cruiser, IMO, I'd get some boxed lowers for the rear (and maybe a rear sway bar, depending on the lower arm design), new rubber bushings in the stock upper arms, new springs and shocks, and rebuild all the FRONT suspension with better springs/shocks/bushings/swaybar... If you run a rear swaybar, then you need boxed LOWER arms to mount the bar (either stock arms boxed or aftermarket). The uppers don't matter for the swaybar.

Dennis, Tony, THANKS!!! Now I get it.

I'm going to do as you guys suggested, boxed lowers with a sway bar, and rubber bushings for the uppers. You are so right about needing the money for other items on my list. Is it ok (or beneficial) to use poly for the frontend? I've also read not to go too big on sway bars. Is that right. Are 1.25 in. front and 1 in. rear too big or stiff? I'd like to improve the handling over stock. I will use new (1 in. lowering)springs. But again, this is an occasional cruiser, not a racer.

BTW - you guys are why many of us are here, to learn from your experience. Thanks for sharing.

Poly are OK for the front-end (I know all my critics are applauding here), not ideal but since they only rotate they will work. Make sure to get greasable bushings and stay away form the poly graphite versions.

Thanks Dennis.

I tried to check them out, as I'm going to be in the market for bars soon, but their site is down. I have BMRs on the 72 and love them and the sway bar I got from them.

a question for dennis...why stay away from polygraphite in the front??

Graphite (powdered lead) does mix well with urethane. In a very short time (relatively speaking) you will need bushings again. The lead deteriorates the bushings, not worth what very little advantages they offer over NVH. Just run regualr poly and grease them often.

FYI Guys,
I got an e-mail from the president of UMI Performance (http://www.umiperformance.com/) explaining that they didn't have uppers for a 67 chevelle when the site was published, but now they do. He offered any assistance possible to meet our needs with his products. They are selling the rear upper and lower tube arms as a set,with poly bushings(I asked about rubber for the uppers) for $200. Guess I can't fault their attention to detail now can I? graemlins/clonk.gif