I just picked up a 12 bolt posi 4.11 rear for my chevelle and I removed the two bushings in the housing to replace them. My question: are these bushings the same as the ones in the control arms? Also, I'm considering replacing the original control arms with an adjustable set that I found on ebay http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2449471180&category=33583 they also make a set for the lowers, what are your opinions on these?

The bushings are the same that go in the ears of the diff that are in the control arms. Don't put poly in the upper control arms because they will bind and you will get wheel hop.

Can't really comment on the adj upper control arms, but I hear they perform pretty good.

i put solid aluminum bushings,adj.upper arms,boxed the lowers and a sway bar.no wheel hop at all.

solid is great for race only use, street cars require rubber. The adjustable uppers are expensive, and most people will never benefit from them. Olds or Buick actually had a factory option for adjustable uppers in the late 60's and it is a very sought aftre option as it is rare, not because it is best.

I have poly bushings in my upper controls. Drive it on the street every day and have had ZERO wheel hop. Just stock uppers with polybushings. Little sqeaky when its cold but the car plants AWESOME.

My 64 El Camino came stock with the adjustable uppers.

Cam

Did any one check out the web site 1967talldeck427 provided? The seller also has adjustable lower control arms (http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=2450948268) . . . why would you want to install adjustable lowers?

Also, I am getting ready to replace the rear upper bushings mounted in the differential. Any suggestions as to an "easy" way to install the new bushings?

dalic, I don't think anybody noticed the link I provided. My same question: why adjustable lowers? I've ordered both the upper and lower adjustable in blue. Figured the upper I can adjust pinion angle, and the lower, will look good through my 18" wheels along side the 12" rotors from baer. As far as the bushings in the housing, I just changed mine: knocked out the center ring, then worked the rubber out and just used a puch and screwdriver to collapse the shell and drive out without too much work. Lubed up the new ones and just used the correct size socket to fit the outer shell and just drove in with hammer.

Don't put poly in the upper control arms because they will bind and you will get wheel hop.

Total poly in the upper arms/housing is bad... It shouldn't give wheel hope on acceleration, but it will make the rear too stiff for good handling, since it will tend to bind.

The upper arms/bushings were designed to flex to allow the rearend to articulate up and down...

If you remember geometry, look at the upper rear setup. As the rearend moves up and down, the arms or bushing have to flex. This flex is either taken by the bushings, the arms, the rearend "ears" or the FRAME... often the crossmember will begin to crack on these 32+ year-old cars...
For drag race, the stiff setup actually works well, but for handling its too stiff. If you decide to stiffen up the uppers, then at least get the additional braces (Hotchkis and Edelbrock) to help transfer the load from the relatively weak upper crossmember down to the main frame...

Adjustible lowers might look cool, but they would have to be properly adjusted (alignment shop?) or the rearend thrust will be off...

Ok, I just did this search and found this.

I already have full poly in the arms. I'm ready to put bushings in the housing. If I put the poly ones in, is that bad? Should I go buy rubber rear housing bushings? Will I tear up my car if I put the poly ones in? I thought poly was supposed to be a good thing? Crap, my rubber ones I just took out were fine. :(

Lots of questions! graemlins/waving.gif

Chad,

I have had all poly/stock upper arms in several cars. The rear suspension was VERY stiff. Seemed to be good for planting the rear tires when launching at the drag strip.

But the cars were always so stiff, they tended to "skip" sideways when cornering AND hitting bumps (even small bumps, roadway "Botts" dots, etc)... Nothing major, but made me a little antsy to attack the corners aggressively...

In my convertible, with NO OTHER Changes, except changing to new rubber bushings in the upper control arm, the handling (the "feel") and the comfort improved dramatically.

Where previously, the car would drop maybe 1/2 inch when I leaned my weight on the quarter panel, it would now drop at least double that... The additional bind of those Poly upper housing bushings was actually supporting some of the weight of the car... and not the coil springs...

The ride is now much nicer, the road feel in corners is better, because the rear is now "soft" enough to allow the tires to remain in contact with the pavement.

I haven't experienced any increase in wheel hop, but my rear tires are not really sticky...

Someday, I plan on getting adjustible upper arms, but I will get the Edelbrock/Currie arms (with spherical joints) AND keep the rubber upper bushing in the housing...

Well, I don't really want to change out the upper arms... Would putting rubber back in the housing make much difference at this point? Or should I proceed with full poly?

Chad,
IMO, I'd go with the rubber bushings in the housing...

After all, new rubber bushings should tighten everything up anyway...

Aside from the increased "bind" of all-poly setup (which will stiffen the suspension), the poly bushings will not do much if anything to improve handling unless you drive aggressively... The rubber deflects easier than the Poly, but they both still do deflect yet hold the rearend position...

Too late. Put the poly in last night. It was really easy with the freezer trick! graemlins/thumbsup.gif

I tried solid bushings in the upper housing ears and rubber everywhere else. Works like a champ so far and the ride is just right!

freezer trick?