Why would you want to use the old tranny if you could use the newer better one with better availabillity of spareparts and tuning parts? "edit, forgot that: no, the old tranny wouldn't fit in"
FLM-towers fit to the traxxas bulkheads, no problemo!
but if you are building your truck form scratch, I would go for FLM hybrid bulks so you could use 1/8 buggy/truggy diffs, well... actually that's what I did
concerning the shocks: I used the buggy shocks from ofna, wich UE sells as supershocks, but the traxxas bigbores might work as well.
as suspensionarms I used the ones from flextek, but RPM should be the best bang for the buck.
edit No.2:
That was the mail I sent gorillamaxx:
"Hi,
I wanted to ask when the G4 chassis are going to be in stock again since they are out of stock in every hobby shop I know and on your site as well."
and this was the reply:
"Yes - please check back near the end of next week. We are hope for a batch to be ready at that time.
George"