283 vaccum canister.

Hello,
I have a recently rebuilt 283. Ran great until I swapped intake manifolds. Went to an Edelbrock, but it would not fit due to the vaccum canister. I took the canister out without pluging the hole. The motor ran until I went for a test drive that is when my oil preasure dropped and this grinding noise started.
Do I need to do somekind of a modification to the vaccum system? Do I need to replace the canister?
Please advise.

Thank You very much, I do have a PCV, but have not plugged the hole until this weekend. Again Thank You for the help.

Thanks again.