To be honest you might just as well fit it properly to test it. As Steve says, you need the gearbox on to fit the starter and it would be very difficult to keep secure without the gearbox mounts supporting the whole lot. About the only thing you could get away with is the driveshafts.
Something you could try, to make sure you're compressions are ok is a 'leak-down' check.......you could then at least identify possible problems with the valves, pistons, bores etc.