I got the TB gasket from the dealer,,,cheap, like $4.
Unless your going to be in the midwest, midatlantic states SE Alaska, I'd do away with the heater plate(a recall installed item),, that gives you 2 fewer hoses to break.
I eventually did away with the other 2 hoses and blocked off that pellet contoled air valve , too. Just opened he screw bit for slow idle, The ICS akes care of the rest.

partubershould be in repository. All aftermarket gaskets will only fit 24 valve models., but dealer stillhas them.

dave h.
'89 Raider V6 5spd;Aisin Hubs;; Gen2 LS: frt. brakes, rear coils;U.C.arms;R.trailing arms;idler arm; rear LSD axle w.disc brakes ;2 battery system for Dog's fan; relocated ECU; custom bumpers;J.Baker receiver;Conferr roofrack; t-bar crank.