How long did it take you to rebuild your

Yeah it really depends on what you mean by “rebuild”. If all that means to you is changing the gaskets and foams then yeah, 4-5 hours is plenty of time. But that’s a gasket change, not a rebuild.

If your heater box needs fiberglass repair, or the doors are rusty and you want to clean them up, or the whole thing is faded and crappy looking and you’re going to paint it you’re going to need more than 4-5 hours.