Has anyone ever tried hand lapping, i'm currently doing a rebuild on my 88 FC
and i'm trying to save a little cash.

 

he he funny you mention. I have a bad 20b front plate, water jacket seal corroded out in to the jacket. I was thinking about grinding the bad steel out and slowly adding steel back in with a tig. I was going to use a small die bit to recut the seal groove and "lap" the plate face back down with a diamond hone. I have tig'd in new steel in to a refrigeration compressor valve plate and "lapped" it down as mentioned above. It worked as per recommended amp draw, so efficiency was correct. Of course new valves were used. I do think I would lap a large surface unless I had a big *** pad and lots of time.