I6 to v8 swap help,,,,,

[jef5150]

ive got a 69 chevy short step, I6(250),4speed w/granny low.I've read i can use my original towers in the original position to mount the 350. Do i need v8 mounts on the block,and bolt those to the towers?? I dont wanna use the old 4speed/ and a muncie would be kinda pricey,so im thinkin id go with a turbo 350, easier install $$. ..Also it looks like the top rivets on the frame at the trans/crossmember are gonna be a "pita" to cut off (2 under the cab)do i need to lift the cab a little or will i be able to get at them with the old motor and tranny out, to install the "auto" crossmember. im aware of the radiator/fanshroud/drive line stuff thanks jeff