Adjustable pinion snubbers?
This car went low 9's with no snubber and SS springs IIRC.
https://www.bing.com/videos/search?q=64+dodge+shawn&FORM=VIRE1#a
It's not the 70's anymore either. Shocks are a bunch better as well. Clamp the snot out of the front sections.
W2360's car had ss springs, rancho shocks, 275/60 drag radials and went 1.46-1.47 60's. No snubber. It's how you set the car up.
Lots of ways to skin a cat with this stuff.