I got some of them and have installed them into a B20F engine but have
not run the engine yet. Since they are made by Sealed Power, I think they
are reputable. The IPD lifters are also (I believe, construction looks
identical) made by IPD. My guess is that they are OK but I haven't had a
chance to prove it yet. BTW if you do take them for a hardness test,
get them tested on the Rockwell "C" scale. Should be about Rc 54 or so.

One problem I had was that they seemed to be a bit LONG. I installed them
with a milled head so that is probably part of the problem. Anyway I made
some shims for the rocker stands out of fender washers, one with a big hole
in it. I ended up having to by 24 washers to get 5 exactly the same
thickness. Washers are made from scrap sheet in a punch press operation
unless you buy them to precision thickness, in which case they cost about 10
times as much.
--
George Downs, Bartlesville, Oklahoma, Central US