air gap install, guide pins on deck!!!

I don't know what size bolts a 340 uses but I do know Edelbrock recommends RTV only on the front and rear gasket faces. I don't believe the head gasket tabs should overhang at all and should end flush with the block if memory serves. You can download the install instructions from the Edelbrock site and it will also give you more info on torquing and such.
Good luck.