'71 442 / Ride Heights / Suspension

[davey]

Hi - am new to forum and wanted to say hi! I see a lot of good advise here and wanted to introduce myself and tell my story as I work on my project, '71 Olds 442. First let me say that I have a lot of knowledge on circle track suspensions and the technical aspect of them. My 442 is going to be for street but I want to make improvements without chopping up the car too much.

First thing I wanted to mention is that I have seen a lot of discussion about rear suspension - but almost none talk about the importance of "ride height". In fact, many of the manuf of aftermarket parts do not really talk about it either, or have recommendations for it (other than offering "lowering" options). To have a suspension work optimally, angles of control arms and relative heights of them are critical. This means that either you adjust your ride heights to make best use of control arm placement that you already HAVE, - or - you have to design your mounting points BASED ON the right height you WANT. Manuf pretty much shy away from ride height discussion because every car is different based on many factors; but you cannot escape talking about it if you want your suspension to work right!

Second point is that almost no one talks about the ramifications of different rear suspension setups and the ability to use your current exhaust system (or one off the shelf). For me, I want the exhaust to come out the rear and be in stock position, and (with the exception of Global West), almost none of the trick rear suspensions allow any room for the exhaust pipes to go anywhere near the stock locations over the rear. This may be fine for many, but it can be a big surprise if you haven't previously thought about it and realize later that you have a problem trying to fit an exhaust to go to the rear of the car, and almost always are going to require a custom exhaust job.

Thanks, just wanted to throw this into the discussion.

-Dave

[davey]

I guess I should have described my build. Right now car is in the body work phase, but am about to start on rear suspension. I figure that there enough off-the-shelf front end components that are "bolt on", where I can worry about the front end later. I am in a bit of a hurry to get the car on the road so don't want to refab the whole front end.

Engine: 455 / 460HP (hyd roller cam, 10.5:1, Offy 4 barrel intake)
Trans: TKO600

Rear:
-9" ford, taken from a race car no longer in use; alum carrier, GM metric disc brakes (3.50 gears at present, have to put in some kind of posi)
-Currie brackets for upper and lower control arms
-UMI Double Adj upper and lower control arms
-QA1 rear coilover kit (may install in front of axle near stock spring location to allow for exhaust)

Have Herb Adams VSE front and rear sway bars

***
I am fighting a little bit with geometry of rear. Seems the Currie brackets move the rear back a little, and to get better angles, it seems to want a 2" ride height drop, but then rear is back a little too far and I will run out of adjustment shortening the control arms. I am trying to work this out on paper before I start actually mounting brackets, so this info is based on math, more than actual measurements.

It also seems that the stock upper control arms are 1-1/8" HIGHER on body mount. A 2" drop and a slighly higher positioning on the rear mounts should make the geometry make more sense, but it just seems so odd that Currie does not tell you (and I asked) that the rears they sell are made for 2" ride height drop. Guy at Currie told me that no one ever asks about right heights or other frame measurements. hmmmm...

Now, maybe I won't notice any of this "optimization" but I just want to do this right the first time.

Btw, have a set of 2.5" Pypes (race pro) exhaust on way, so I can see what kind of room I will have.

Any thoughts or similar experiences?

Thanks,
Dave

[Taman]

I am having the Heidt's 4 link rear suspension. I was not able to run tail pipes. I would like to but , that's the price of cornering.I also had to move my electric fuel pump. I had it mounted where the stock cross flow muffler went.