Doing same swap 305/350 in 53 GMC Longbed. My plans are to cut center rivet crossmember but leave ends on frame , use center motor mount on engine and new rear trans crossmember. I have a mustang 11 ifs and it looks like side mounts will be partially welded to new ifs crossmember. has anyone done this? Would like to move back to avoid cross member also when you refer to cutting toe board do you mean the lip on bottom of cowl. Thanks
Where, and how much to cut depends on how far you plan to set back the engine and how low you go with the engine/transmission. You'll need to mock the engine/transmission on the frame and then place the cab into place, scratch your head, and start cutting.
Carl
