Fel-Pro gasket set P/N MS 91022 comes with two gaskets, distributer o-ring and a tube of black RTV.
Good book: How to rebuild GM V-6 60 degree Engine by Tom Currao, Motorbooks International.
Ebay has Trooper service manuals on CD. I havent tried one yet but will. My Helms is getting very dog eared.
Gm 10-30 Light Duty Truck 1987 Service Manual covers the 2.8L TBI engine better then the Trooper manual. Don't know if the GM manual is on CD, I lucked into my set at a used book sale for $.50 each.
John in Lv, good luck

3 90 Trooper V-6's, 5 speed, 4.3L TBI, 31" BFG AT's, Fender Flairs, Bored intake, 1.6 roller rockers, MSD Coil, Jacobs Omni ignition. Heavy duty torsion bars, Rancho 9000 Shocks CAN'T SPELL, TO OLD TO LEARN, GOD BLESS YOU IF YOU CAN.