I'd recommend NOT removing the housing. ...Extra work and potential for dealing with a corroded bolt, etc.

If you are rebuilding a motor for the long haul though, and its out of the car, etc., it might be a nice thing to at least replace the old bolts which might be eaten away with corrosion from the aluminum.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.