How to replace intake bolts?

Thats funny, that part number has been on national back order for 6 months. You can buy the same bolts at Home Creepshow for $6. Nothing fancy, either plated or I sometimes use allens with washer. 5/16 x2. Stock are 2.25 but not common size. Pull one and take it with you.

Cool thanks, just make sure it has a shoulder, right?