The factory decided to change the length on the front segment of the rear leaf springs in 1964 from 20 inches to 22 inches, all the Super Stock springs I know of are 20 inches long on the front segment
The reason I'm mentioning this is if you have the shorter front half and did not use the special front hangers it will move the rear spring eye forward and make the rear shackle not be angled to the rear like stock was
I think that the bouncing and poor 60 Ft. times are caused by the shackle being pull forward under hard acceleration which ends up pulling the back of the car down unloading the tires
If this is the case you can change the front spring hangar or make a new rear one to get the angle better
Let us know what you find and decide to do

64 dodge 3960lbs - 572 HEMI 30"x 9" Hoosier radials 20-22 lbs of air - caltracs with the split mono leaf spring - Rancho 9 way adjustable shocks 3 clicks from tight consistent 1.44 60' foots - 90/10's up front.

I can't think of a single reason to use SS springs and/or a pinion snubber. Ever. [/quote]
While thier window of application has shrunk over the decades, to say "not ever" doesn't make sense to me. They still work WITHIN LIMITS, and combined with good enough shocks, the only change in performance would be the ET gains from a lighter wallet.

While thier window of application has shrunk over the decades, to say "not ever" doesn't make sense to me. They still work WITHIN LIMITS, and combined with good enough shocks, the only change in performance would be the ET gains from a lighter wallet. [/quote]


Well said. I've many times "used what I had". Sure if you are buying parts not on hand then the choice might be different.
Doug

I went a 1.33 w/Rancho 90-10's ft and old 5-ways in the rear on #4...........

Thanks for everyone's help. This helps to get me headed in the right direction. DoubleD awesome ride!

I wore out a set of rancho 5 ways then went to viking da shocks all the around with the more aggressive valving in the rear.Still and forever tuning.... with spit mono CTs.They have been consistent as I turn the power up.Adjustable boost is a wonderfull thing!

We had similar issues and went through Comp engineering shocks, Calvert's 5 ways - then 9 ways - AFCO Big gun D/A's and finally Menscer re-valved the AFCO's. Buying a good quality / rebuildable shock now, means you won't have to replace it when you step up (I really should listen to my own advice sometimes)




Photo taken By Paul Green, Santa Pod UK Sept 6th 2018

The OP has a street car.

Ahh....OK my bad, but that's how I started

Cool pic. And no kids your ricer won't do that! That's what I tell my son about his Saabaru.

Don't they all start as street cars! - I built mine for the street!

x 2; the amount of front suspension rise from the static ride height played a bigger part than I expected in getting my car to launch without unloading the rear tires after the hit.