Hughes and Lunati have "retro" roller lifters you can run in LA small blocks. They are designed with the oil hole lower on the lifter. Hughes told me most of the issue with the oil hole possibly being "too high" for an LA block is a 340 block. Also told me they never saw an issue with a 318. If you go on the Hughes website, they have pictures and an explanation, more in depth which I mentioned.

There are also .028 head gaskets at a decent price or you can get a .027 at about twice the price.