I'm rebuilding the front end of my 66 convertible cruiser and would like to hear from anyone out there about their experience with the polygraphite suspension kits (good or bad). My project started as a SB to 396 BB conversion with the addition of dual master and disk brakes on the front but once I got the 350 out I noticed that the rubber on the suspension parts was all original and pretty beat. I have already purchased Moog 6204 OEM BB/noAC springs and was thinking of using the poly bushings but have heard and read complaints that they are noisy and hard. This car has always been a good driver and I want to keep it that way.

Poly-graphite bushings shouldn't squeak, the graphite in them is a lubricant. In the front suspension they work good since both control arms move up and down on parallel axis. They will make the ride stiffer if used in the rear suspension. Since the upper and lower control arms rotate on different axis something has to give, rubber bushings will, poly bushings, not very much.

I have poly in my front suspension, about 5 years now, no squeaks.

I also have poly on my 71, they squeek some, but I can only hear it in the driveway by pressing up down on the car. I can't hear them on the road or any time driving, even going up drive ways. If I can't hear it while driving , it doesn't bother me.
But the front end feels nice in firm on the road and curves.

A side note and more important than the squeak issue is that graphite and urethane are incompatible chemicals and the graphite will lead to accelerated deterioration of the urethane resulting in the replacement bushings wearing out faster than the original rubber.

Another fact to consider is the cold flow properties of urethane which lead to the steel cross shafts "settling” into the urethane egg-shaping them and resulting in poor control arm retention which will cause odd handling at high cornering speeds as the camber/caster changes in a non-linear arc.

A side note and more important than the squeak issue is that graphite and urethane are incompatible chemicals and the graphite will lead to accelerated deterioration of the urethane resulting in the replacement bushings wearing out faster than the original rubber.

Another fact to consider is the cold flow properties of urethane which lead to the steel cross shafts "settling” into the urethane egg-shaping them and resulting in poor control arm retention which will cause odd handling at high cornering speeds as the camber/caster changes in a non-linear arc.

Interesting, I have poly, not poly-graphite bushings, lubed up with goop that comes with them. One thing about poly or poly-graphite is they're easy to change if they due wear out. You don't really need to replace the shell, just slide out the bushing, grease up the new one and slide it in.

i have all poly bushings in my chevelle red ones drives good no squeaks

I removed the forty year old stock G. M. stuff. I went with stock rubber parts. If the old stuff lasted forty years. I do not want to re-invent the wheel and roll the dice !
The Org. rubber parts work well in any weather in all parts of the world, For me this is a very good track record.
Whats in your wallet ???????????????
Bob

I have urathane bushings in my Camaro...and they do make little noise.
I just put PST bushings in 68 Chevelle, full kit with disc brake upgrade and big sway bar. 67 Elcamino has boxed rear arms with PST bushings. very
good hookup and no noise Jay

I've got urethane bushings in the Firebird front and rear. They squeaked like hell after a couple hundred miles, until I hit them with some dry film lube. They've gone a few thousand miles since then, completely quiet.

In 5 years, the new rubber ones will be as soft as the old ones you take out. If you are going to drive it, use poly bushings. The improvement in handling is like night and day.

Thanks a lot for taking the time to help out with the info guys. After reading your replies and looking at some other info I'm going to go with the PST system.
Any thoughts on shocks? I will probably go with hydralic over gas since I once had a problem with gas shocks going flat due to the car sitting for awhile and since this one is a convertable and does not see much action over the winter months.
Victor

I'm rebuilding the front end of my 66 convertible cruiser and would like to hear from anyone out there about their experience with the polygraphite suspension kits (good or bad). My project started as a SB to 396 BB conversion with the addition of dual master and disk brakes on the front but once I got the 350 out I noticed that the rubber on the suspension parts was all original and pretty beat. I have already purchased Moog 6204 OEM BB/noAC springs and was thinking of using the poly bushings but have heard and read complaints that they are noisy and hard. This car has always been a good driver and I want to keep it that way.

The polyurethane bushing kits for front A-arms are typically hit or miss when it comes to squeaking as you can see by the previous responses. The problem is that the A-arms were never designed for polyurethane and the steel bushing shells have no way to properly lube the bushings. They usually come pre-lubed but the lube washes out over time and squeaking is the typical result. A properly designed tubular A-arm utilizes internally fluted polyurethane bushings with grease fittings. Our A-arm bushings grease from the inside out so that the thrust surfaces also receive lube. If a high quality silicone is used, thousands of squeak-free miles are no problem...