Vintage Mustang Forums banner
1 - 3 of 3 Posts

1,667 Posts
Discussion Starter · #1 ·
My 8 inch converter will be here tuesday. They said I should foot brake this thing to 3000 and then it will flash way up to between 4500 and 4700 rpms when I leave. It looks like this will be a BIG adjustment.

I'm just wondering what I will need next to make this thing go straight. I have my new mid-eye springs. These are stronger than stock 4 1/2 leafs but mid eyes with up to a 1 inch drop from stock spring heighth. I also have some good racing type shackles with neoprene bushings for the back. I run drag shocks and Southside Lift bars.

So far I've left my rear shocks pretty tight so they don't let the rear end squat a whole lot. The gears are Richmond 4.62's in the stock 8 inch rear end with a traction lock and 27 x 9 slicks. My third member is a heavy casting chunk that is a lot thicker and stronger than the stock one that I pulled out. The Southside lift bars are fairly tunable although its a bit cumbersome because you have to custom make shims for it.

What about pinion angle? I don't know anything about that. I don't think the lift bars allow much in the way of rear axle twist up. I can adjust my pinion angle either with wedges or by adjusting the shims on the lift bars.

What about a pinion snubber? All I have is the stock one. It looks like it allows a lot of travel before it would come into play. Should I think about getting an adjustable snubber?

Do I need a neck brace now? LOL.

You can see my 65 fastback at:

there is the stock snubber that mounts to the underside of the car. There is also one that
bolts to a flange that mounts on the front of the rear end housing. I think one way is nine
inch the other is 8 inch application. Look underneath some old bronco's (ford bronco's that is).

M.C.A.# 50000

10,588 Posts
A high-back seat will do...*G*

The converter slip will be easy to get used to...just be careful to not overheat the fluid too much playing around on the street...

To transfer weight adequately, you're going to need to get the car to pivot on the rear axle a bit better than stock....softening the compression on the rear shocks and softening the extension on the front shocks usually helps.
You still want the car to move up and down on the rear spring fairly easily so keep that in mind when adjusting your traction bars.
Try for a 1-2 degree down angle on the pinion CL in relation to the crank CL.
An adjustable pinion snubber can help with controlling housing rotation and is usually used in conjunction with a heavier leaf spring (like the 4 1/2 leaf) as the primary traction devices...I've never tried it with a traction bar so don't know what to expect.

Getting the rear tires to plant is the key when using a stock-style suspension...the 8" converter will shock the suspension more and this can either help or hurt depending on the way it's set up.

Take a look at how Alex Denysenko's car plants the tires on the way to another high 10 second run in Super Stock...
Rotating the car over the rear axle allows the 289 to build more rpm, hp, and torque as the car launches and ultimately is the key to the car's performance. If the car had to convert that same energy into straight forward motion immediately, as mine is set up to do with the W, the smaller engine would have a harder time of it.

Best way to check all this is to get to the track and test...and log the changes and results...

Good luck! And enjoy the neck snaps..*G*

1 - 3 of 3 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.