My solution was a aftermarket manifold,and didn't even know. It is a victor340 manifold in my case. Has a built in air gap and no heat riser passages. Works really well on this motor and never boils the fuel. I have driven it in very hot conditions like 110+ degrees and it does great. No way can you leave them open nowadays with the crap gas I'm guessing. I wouldn't be afraid of using old soup cans or something like that.