boy, i dont know it does depend on what kind of offroad track you run on like if its rough and bumpy you dont wont to run "50" or "60" wt in the shocks for sure more like "35/30" with the stock shocks and it should jump fine.
if its a smooth track i ran 40/35 in a indoor track i ran 60/50 and it took to much roll off in the corners.
do you have to run yours as a box stock sc ?
i, never had my plastic caps pop off at all as long as you dont have to much pressure in the shocks your fine.
you, can lower the" rear body mounts" as low as you can that will defielty help handling and jumping rpm makes a front body mount were you can run it pretty low i have one i noticed the diffrence in a box stock class i ran.
oh yea put holes in the rear window of the slash that helps also because air can get sucked up the body.
slashs, arent the best jumpers anyways compared to other raceing sc trucks to be honest in stock mode compared to others i seen jump and handle.
i mean you can get the slash to handle good enough to be competive just needs tuning.