Ansen Small Block Valve Covers

Make sure the upper edges of the covers are not interferring with the intake
Funny story - I was removing the intake from a 340, and couldn't get it to budge. I went so far as to hook my cherry picker to it and all that did was pick the front end of the car up on the suspension.

It took a while but eventually I realized the valve covers were holding it down. It's a wonder I didn't break something or hurt myself before that.