On an LA small block, you have 6 intake bolts for each side. The front bolt and rear bolt on each side go into a blind hole. The 4 bolts between those all go into an area where oil is draining back into the lifter galley from the valve cover area, and any or all of the 4 middle-ish bolts on each side will wick oil up the threads and pond up on the intake if you don't seal them up. I just installed an aluminum intake on my fresh 273 the other day. I used a few rounds of teflon tape and also sealer like Steve posted above. I did the 4 bolts on each side.