ORIGINAL: choops01

Hello All
Have been building my hellfire SS over the last couple nights. (taking my time).
This is my first 1/8 scale build and I never realized how many parts there were in these things.
Did anyone fit the filler blocks in the front bulkheads which hold the diff in place?
I have built the diffs and there is a little grinding (gears feel tight) between the ring and pinion. Is there a break in period with these or is something not correct?
Also installed the front suspension and the drive shafts fit very tight in the dif cups. I feel that this will free up after I run the truck a few times. Is this ok?
And finally are there any simple mods I should make to the truck as I am building it?
Thanks for your time.
Steve