1966 with gear vendor

68 should be easier
not really...
two basic ways to go on and A, mod the crossmember and lower the whole thing so you only need to beat on the floor, or cut the floor and hang it on the stock mount. the lower you hang the trans, the more work you'll probably need to redo the exhaust.
8.JPG

2 1/2" TTi crossover / GV heater before eliminating it
TTI crossover.JPG

you'll love it once you get it done