Well, the holes in the VDK pistons are intended for the revo and you run 30-60wt in them, but on the stampede, I would have had to run 10-20wt, which then would be more likely to leak. So after drilling them out to 1/16"... I had to go up to 80wt to get a decent feel from them.
FYI, most of arrma's run on 80wt/1000cst oil.
I just put losi or dynamite 80wt (a bit higher than 1000cst) in my xmaxx after rebuilding them. Also put a bit stiffer spring on it. Didn't get to test it out much because my main input gear/center diff gear died half way through my first set of packs... so not sure if it will be too stiff or not. Pretty sure I had 60wt in them with the stock springs. Trying to get it to bounce a bit less on the big jumps.
Just checked on traxxas site to see what the "big bore" shocks lengh was. They just show them as "xx-long". If you look at the pair of xx-long "big bore" shocks, they list all the things they fit, which include the slash/hoss/rustler, so I'm guessing the GTR xx-long would work on the tmaxx also:
Big bore xx-long:
https://traxxas.com/products/parts/2662
GTR xx-long:
https://traxxas.com/products/parts/7462X
You would have to figure out springs to use though... they would be larger ID than the big bore springs and you would likely need to find heavier than whatever they list as the "2.5 rate" springs that come on the big bores. The springs on the big bores are painfully soft to begin with, much like the stock springs on the ultra (plastic) shocks for the t-maxx.