Does it use the LST1 parts Olds? If it does GPM and Hot Racing still have a better selection of hop ups still available for the LST1 than they do the LST2/XXL. Just a thought.
For the arms out to the wheel nuts, it's the same as the LST1. The two speed/trans is the same between LST1/LST2, but differs on the aftershock. First thing I'd upgrade would be the arms to LST1 arms with lunsford turnbuckles in the arms and the LST2/XL 2 speed assembly.
Later I'd upgrade the engine mount brace to a cnc vs cast version, lunsford turnbuckles for the front/rear (or stock up on stock ones as you will bust a few).
My aftershock was pretty bulletproof when I sold it.
RPM arms w/lunsford turnbuckles (Ran stock arms for break-in, installed RPM before I busted any. Busted 2 RPM turnbuckles and bent the other 2 within the first tank, replaced with lunsford and never looked back)
Lunsford turnbuckles all around (busted 5 or 6 stockers, one of which caused my front axle to turn so far that it busted the cvd... didn't want that again)
Roll bar I made
Center -> front alloy skid I made (got tired of replacing chassis rails every other outing)
17mm hubs (burned out 14mm hex's after installing LRP)
Dynamite CNC Engine Brace (busted 2 stockers)
LST2 2-speed (torched stocker when I installed the LRP)
LST2 pipe (never ran stock, took everones word on the fact that the stock pipe was junk)
4mm upper shock mount bolts (busted a few stockers before this upgrade)
RC Raven dual rate springs (yellow was too stiff, RC Raven was great)
carbon fiber brakes (stockers started to grab, so upgraded to a single 4mm CF and 176oz throttle/brake servo)
Alloy diff collars (broke 2 or 3 of these on the front before upgrading)
HD Diff upgrades (Never had issues, but upon maintenance, saw that the x pins were eating into the plastic. Ran original gears for 10+ gallons, did the upgrade 5 or 6 gallons in. Longest lasting diffs I've ever owned)
50K diff oil (didn't like open diffs with grease)
150cc LST2 tank (for more run time)
HD center skid that protects the pipe/spurs (bent a couple trans input shafts before getting that)
I also got a really nice chassis deck for very cheap on a sell out sale stormerhobbies had with Hardcore Racing titanium stuff. Paid $40 for a $200+ chassis. I don't think it was necessary... but mine was tweaked from busting the chassis rails 4 or 5 times before I installed the front->center skid. So I figured why not buy that vs replacing with stock.
I ran smaller tires/wheels on it as well, which created less leverage when I landed bad or hit something. I ran +2 pinions on an LST1 threaded bell. They were +2 over LST2 stock. Again, not a "necessary" change, but I ran it like I stole it and never bent/broke an RPM arm or lunsford turnbuckle or shock shaft. Not unlike my buddies that ran LST2's in stock form.
I ran stock everything else in stock form, c-hubs, axle carriers, chassis rails, shock towers, diff gears, spur gears, center and outer cvd's, header, steering servo setup, upper chassis plates/stand offs and trans (did a gear flip mod in the trans to add +1, but stock otherwise).