the shock kit is a lil tough of a find b/c it had some 1.0 parts in it (notably the shock ends). give those to a 1.0 racer and get some 2.0 shock ends for ur kit. then ur set.
the metal carb link for the losi 350 is a must over that plastic junk piece they give u. i'm hearing some of the new fresh examples of the 2.0 RTR have them on already. idk for certain. dynamite (thus horizon) sells a replacement part for bout 6bux that fixes that issue forever if u have a plastic piece. i forget the p# or i'd tell u. its in the 'losi 350 engine who makes it' thread.
i think the servo saver thing is the use of a truggy or 1.0 spring to improve the system as a whole. i also believe that new kits have this running fix on them. not sure what could tell you if u have the running changes on yours or not b/c there are a few.
R