Hot Rods Pinion Angle/Trans Angle For My '37 LaSalle W/Turbo 400

In all of my years at GM that has never posed an issue. At no point was a pinion angle selected for where it would end up at maximum torque, on a hard launch.

The pinion angle is selected to be where it will be correct at freeway speed, with average cargo/p***enger load, as that is where it will be for the vast majority of time and revolutions.

Every single GM vehicle that has a live axle produced, from just after WWII, to this day has a positive pinion angle, as do the vehicles from Chrysler, and Ford.

The critical factors are parallelism, and keeping the operating angle as shallow as it can be, given ride height, ch***is construction, and other considerations.

 

Here is an exerpt from a guy who wrote a book called :
"Building Hot Rods"

This guy builds ch***is and suspension systems for a living.....specifically for Hot Rods. He has a no nonsense gr***roots way of presenting the information. This book is chocked full of great information on EVERYTHING about building Streetable Hot Rods. Get it on Amazon.............

So here is his explanation of what, how, and why....specifically for Hot Rods.

 

Exactly! You set your angles for the way the car will be most of the time, not for occasional hard launches, or bumps in the road. If you set it up for where it would be perfect for occasional launches it would vibrate under normal driving.

 

So....See my Avatar which is what I'm working on setting up a new ch***is for it. Everything is at ride height and suspension loaded. If my 9" Ford pinion, currently set at 2 degrees up, is located ABOVE the transmission output shaft ,which is 4 degrees down, and I have rear coil overs with adjustable 4 link rear suspension, and no room to change the engine angle. Given all this, am I ok at leaving it at 2 degrees up? Zero? 4 degrees up?