Best way to refurbish an intake manifold?

[AC_Schnitzel]

Stocking up on parts to do my 2.7i swap and just got a crab from a 325i.

What is the best way to clean the inside of the runners, and to prep for paint?

[TobyB]

Crab cleaner, obviously...

Or carb cleaner, if you prefer. Berrymans. The nasty shit.
Gets the cosmoline off the outside, too.

Honestly, the inside is just going to get gross again...

Lacquer thinner on the outside, followed by wax and grease remover, is good if you're going to paint it...

fwiw,
t

[Massive Lee]

Beadblast and respray. No clear as it will turn yellow with heat.

[JimmyP]

Beadblast and respray. No clear as it will turn yellow with heat.

^^^ This ^^^

[325e '87]

I just took mine off to do new coolant lines but I also cleaned up the crab with carb cleaner and a brass detail brush. The detail brush made quick work of the general yellowed cosmoline and also I cleaned up the injectors, injector mounts, and restored the true shape of the injector dome.

[MSGGrunt]

Blast and have powder coated in a black, or color of choice, crinkle finish and fly cut the high spots in a milling machine.