I had BBK's on my 96 Cobra. I used Ford gaskets. I've used Fel-Pro's as well and they didn't leak.
Do NOT use the stock studs/nuts. The studs are too long and it gives trouble when installing and removing the bolts. You need end wrenches to get the bottom bolts tight. These a PITA to do in the car. I'd drop the K-member if I was you. Anyways, get some nice bolts and ditch the stud/nut thing.