New member, old 78 cobra owner

Hi guys! New to the site. I own a 78 cobra which I plan on doing some work on. Need some direction on parts and info. Its a V8-4 speed car w/ t-tops. Ive owned it since 1986. The engine was rebuilt in 1993 and has maybe 500 miles on it since. Its a 40 over early 302 W/ported 289 heads@chevy valves. It has the old solid lifter SVO cam 512/536 lift 238/248 duration. The problem Im having is a slipping clutch and lousy transmission. What would I need to do to put a healthy c-4 w/stall into it? Would any other STRONG manuals fit in that car? Any responses are appreciated. I live in Akron Ohio if anyone wants to shoot the s....

Thanks for responses guys. I dont think an older toploader would fit because it uses a side shift design shifter. It would be an ideal replacement if it didnt require major modifacations. Im starting to think the c4 swap is the only way to go.