Check the housing surface!
My XR7 had the same problem. Check the T/S housing side that goes against the gasket. I used the good FelPro gasket and it still leaked. After looking at the T/S housing I noticed the bolt holes were dimpled toward the gasket. What this does is cause the T/S housing to spread the gasket and bottom out on the manifold giving the impression the T/S housing is tight. Take your T/S housing and put it on a flat surface. Take a hammer and tap the housing around the bolt holes until they are flat with the rest of the T/S housing. Get a new FelPro gasket and put a little RTV gasket sealer on it. Then install the T/S houising and torque the two bolts to the proper value. That should do the trick!
Hope this helps!
Ed Springer
90 Black XR7 5-speed: 70mm TB, Fresh Air Intake, '94 Supercharger, 5% SC Pulley, Raised SC Top, I/C Fan, Under-drive Pulleys, 190 l/h Fuel Pump, 36# Injectors, Headers, Magnaflow Muffler (no cats) with stock resonators, 3:27 Gears, Ripper Shifter, 73mm CL MAF (Blue Tube), Magnacore Wires, NGK Iridium Plugs, Royal Purple Lubricants and Rear Spring Air Bags.
94 Red SC Auto: 70mm TB, Fresh Air Intake, Stock 90 SC Pulley, Raised SC Top, I/C Fan, 190 l/h Fuel Pump, 38# Injectors, Headers, Raven Muffler (no cats) with stock resonators, 3:73 Gears, 76mm CL MAF (Gold Tube), Magnacore Wires, NGK Iridium Plugs, Royal Purple Lubricants, TRANSGO Shift Kit, Pro-Torque 2500 Stall TC, Haydon Auxiliary Transmission Cooler, Tokico Struts & Shocks, American Racing 17” Sniper Wheels, Michelin Pilot Sport A/S Tires and 235 RWHP with 315 LB-FT Torque.