Ride Height stance for a 1978 Pontiac Trans Am

by **69_RAG_TOP** on Wed Aug 03, 2011 10:55 am

I have always liked the look of a slightly higher rear stance on the late second generation Trans Ams.

Perhaps this is a left over desire from the days when I was a teenager and put shackles and heavy duty air shocks on my 1968 Pontiac GTO so that I could put L-60 X 15 Tires fiberglass belted tires on 8 inch Crager S/S chrome Mag wheels.

Those were the days of using washers as spacers on those cars...lol

Anyhow, those days are gone and now I am running modern BF Goodrich radial tires on 8 inch diamond spoke alloy wheels.

This is the highest that I am willing to go without sacrificing the handling, performance of the WS6 suspension.

Thanks to a recent purchase of a set of professionally restored 7 inch diamond spoke alloy wheels by F Body, I plan on building two sets of tires for this Trans Am and for my next one.

by **mr71transam** on Wed Aug 03, 2011 12:56 pm

Larry have you done anything to your Bird other than change the Wheels and tires?

by nap on Thu Aug 04, 2011 9:26 am

Larry,

One of my 1978 Bandits is about as high as the one pictured. I am going the opposite way with mine. I feel there is too much distance between the tire and the bottom of the lip of the wheel well. The Bandit in question is a WS6 and I looked underneath and found 5 leaf springs. An owner previous to me changed it. This is incorrect for a WS6 Bird. All WS6 birds have a 4 leaf spring. Non WS6 cars have a 4 leaf spring also, but the difference is the spring rate. WS6 birds are suppose to be 126 while the non WS6 spring rate is lower.

I called up Eaton and they have a direct replacement for the GM spring. The old GM # is 481132. This number ties right into John Witzeke's report on the W72 engine. Part of the report includes details on the WS6 package.

Hopefully, I can get the other Bandit back on the road and show you the new springs at a Panera Bread cruise.

Later,

Jim

by **69_RAG_TOP** on Thu Aug 04, 2011 10:45 am

Most Trans Am fans are either proponents of the stock look or the higher ride stance set up... I know of no TA owners who have 'lowered' their cars.

When I go to shows or cruise I look at the rear stance and ride height; also the wheels and tire sizes.

I have seen some guys running Nitto Extreme 255-50-17 tires on Boyd Coddington 17" Smoothie II' wheels.

A lot of 1978 Bandits are as high as mine. If you are running 255-60R-15 tires on the rear the space will be larger.

Some people run 235-60R-15 up front. I have seen 275-60R-15 on 15x8 wheels or 295-50R-15 on 15x10 for the rear tires and 245-70R-15 for the front tires.

At a cruise I saw a blue 1970 that had 15 x 8 with 295-50R-15 with the fronts with 235-60R-15 on 15x8's. I think that you would need to watch the back spacing too.

As far as the number of leaf springs, four or five and the leaf spring rate, this will also be a factor in the ride stance height.

A lot of these cars have been molested and altered over the years. Thanks for pointing out that WS6 birds have 4 leaf springs but Non WS6 cars also have 4 leaf springs, but the difference is the higher spring rate for the WS6.

by rkellerjr on Thu Aug 04, 2011 2:40 pm

Well, now you know of one that has lowered his Smile

Here is my stance. Front end has lowered springs and since I wanted a rake in my stance I opted for four leaf springs in the rear. Entire suspension has been replaced. when I lowered it the first time I didn't like the rear as low as it was with the pro-touring rear leafs. Here it is completely lowered...

And now with the rear leaf's replaced with stock and front end not changed which was a 1" drop ...

by **69_RAG_TOP** on Thu Aug 04, 2011 4:40 pm

Rich,

Now I know of a Trans Am that has been 'lowered'.

However you replaced the entire car's suspension from front to back, not just the rear.

The stance of your car looks best in the bottom two picures... my two cents.

It also depends on what tires you are running on those stock Rallye IIs. Are those 245-60R-15 BFG tires?

Back in the day when you had little money, the easiest and cheapest way to raise the rear end is with spring shackles .

by rkellerjr on Thu Aug 04, 2011 6:28 pm

I'm running stock tires which I "think" is 225-70r-15's. I "think". I'm not getting up to look Wink

unless you really have to know. Shackles is a good way to do it and that was my first try to raise the rear up but it didn't do as well as I'd like so I replaced those springs.

Thanks on the compliments on the car. The pro-touring springs in the back were just too low. When I hit a decent hump the suspension would hit the body stop bushing so it needed to be changed. The last three pictures are the same stance just a different view of the car. I too like the current stance of the car. Looks very "muscle". Can't wait to get some real meats on the car.

Ride Height stance for a 1978 Pontiac Trans Am

Ride Height stance for a 1978 Pontiac Trans Am

Re: Ride Height stance for a 1978 Pontiac Trans Am

Re: Ride Height stance for a 1978 Pontiac Trans Am

Re: Ride Height stance for a 1978 Pontiac Trans Am

Re: Ride Height stance for a 1978 Pontiac Trans Am

Re: Ride Height stance for a 1978 Pontiac Trans Am

Re: Ride Height stance for a 1978 Pontiac Trans Am