I'm running a 24t pinion on my 8.5 X12 with a 78 spur, you need the smaller spur or the drive shaft can hit the spur. I have E speed hangers on my dry car but not on my wet car. You need short rods to fit them.
We use grass so similar to astro and I have blue ft and silver rr springs and currently on 35 ft 25rr oil but may change that although it will get you started.
The only weight I've added to my car is a lump of brass behind the servo.
I still use a stick pack across the chassis but many cut the walls down and use saddles side by side or in a kind of T shape right up to the servo.
Just drive it for now, it's a whole different car to a B4, I love mine.
