340 cam for 318

I’ll mention I’ll be riding the lifters, unused, but new 25 years back. I’d trust them more than a new set of lifters.

I’ve never heard a bad word about Howard cams either.
That Howards linked too is a decent grind, except for the 112 LSA. You NEED a 108 or even a 106 LSA. What I would do is send your old core to Oregon Cam Grinders and let them grind something similar to the Howards grind but on a 106. If you put something on a 112 in that, you're not gonna like it.