Normally the gasket is enough. An extra gasket could be used if needed. Chevys can run into distributor clearance problems being the distributor mounts to the intake rather than the block. If the distributor won't go all the way down, it may not be correctly engaged in the oil pump. The intermediate shaft goes in from the oil pan side. Check the fully engaged clearance with no gasket.
Bull Nose Formula/ 461/ Q-Jet/ TH400/ 3.08 8.5 / R44TS.
Edited by - Blued and Painted on 12 Oct 2017 10:52:51 AM