I'm still on the fence about swapping my manual gearbox out for an power unit before I install my 400. I'd like to try the manual set up but if it's gonna be a major pain to swap with the engine in there I may just go ahead and go with the power unit. Anyone have experience with this? Thanks for your input.

It's not that bad swapping with the engine in. Go with what you think you want. Anything can be changed later.

I've taken out the power steering gearbox while in the car, So I do not see any major issues. Sure it is easier while the motor is out but very doable with the motor in.