I would be real scared to put new lifters on a 42 year old cam and some reason the solid lifters are even more expensive then hydraulic lifters.
I am curently porting a set of magnum heads and I will throw in an XE 268 while I am swapping the heads. I also have a set of 1.7 mopar roller rockers I may throw on there while I am at it.
I am not causing global warming, I am just trying to hold off a impending Ice Age!