My head is supposed to arrive Monday (Thanks Tom!) and with the roller rockers, block decking, and head milling... well, I'll need new pushrods I'm sure. I took an old lifter and tacked it so it won't compress when I go to measure for new pushrods. Think it will work, or is there a better way...?

Yes, just make sure it fits the lifter bore smoothly still. Welding on them makes them distort and it can become stuck in the bore and you might not realize it if you just use checking springs.

Will do, thanks!

I took an old lifter apart and loaded it with washers and I think a ball bearing, until I got zero clearance while the spring clip still snapped on.

I was going to do that, but the lifter I grabbed wouldn't disassemble, so I figured this would work.