Advice needed) Things to replace while I refinish the intake monifold?

[mnmnmmm_]

Hi, I'm planning to refinish the intake manifold on my 1991 325i

I saw a lot of posts saying that this is a good time to replace the o-rings and washers for the oil return pipe

Besides these are there any other items that can be replaced while I'm in there for peace of mind?

I'm also replacing all IM gaskets of course,

Thanks in advance!

[ADEN]

Injector seals.