Pinion angle changed?

[toomanymodz]

When I purchased my adjustable uppers, I set the pinion angle to about 3 degrees. After going to the track and pulling some 1.47 sixty foot times, I was under the car and decided to re-check it. It appeared to have changed, so I turned the adjustment several turns (maybe 5) to shorten the upper control arms. They now measure 10.75 inches. I believe stock length is 11.125.

Either I didn't have the pinion angle set correct to begin with, or is it possible to bend the frame where the upper control arms attach to?

I have since purchased a digital angle meter, so at least I can set it more precisely this time. But it's on the back of my mind, did I bend something. ?

I have these reinforcements, I would think this should be adequate for my horsepower level.

 

[Chuck Leeper]

Sum ting wong. Either it was wrong to begin with, or?
Changing by 3/8" is a bunch, for a stock location mounting layout.
Where do you have the lowers set, assuming they are adjustable, too. If not, what length are they? Stock, or? Bushings are? Mounts ok?
Last ?. How did you do the measurement?

KevinS is a member, here. He has a website, w/ good info on it.
https://www.turbobuick.com/members/kevins.285/

 

[toomanymodz]

I haven't heard anything about these frames bending, so I'm doubtful that I tweaked anything, although there are some bars that some vendors sell that tie the upper mounting point to the lower mounting point. There must be a reason they sell those.

The lowers are stock, but have been boxed with some beefy steel welded inserts. The lower mounts are also reinforced. Bushings are poly.

I measured the driveshaft angle and the pinion yoke angle. It is difficult to get a good reading on that without dropping the driveshaft, which I didn't do this time, so that 'might' be the issue. The gauge that I had at the time was plastic gravity dial and hard to read. I've since bought a digital gauge and I can 'calibrate' it on the driveshaft and then it will do the math when I stick it to the pinion yoke.

 

[Boost231]

Possible the arms where in a bind or pinched in?

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