intake spacer?

i need a intake spacer so i can put my tall valve covers on. i have a stock intake and a 2 1/2 cowl hood. i would like to use the 1 inch spacer to give myself plenty of room but would it hurt the performance of the car? should i get a 3/8 or 1/2 inch instead?

I'm not sure on the stock intake or EFI intakes all together. But I know with carb intakes a spacer will normally add some HP on the top end due to better fuel atomazation. That wouldnt happen with an EFI intake though. But to answere your question no I dont think it will hurt performance.