Yes as in anything is possible but I would simply sell the 5 speed bell housing in favor of a 4 speed bell housing. The clutch should work fine as long as it has 1 1/4" - 10 spline input.
Ah so the flywheel and clutches are the same 5sp to 4sp? Ok then I could go 4sp bell house, reuse the flywheel and flexplate. I would replace the clutch with new while I was in there.
