Get some plastigage and check the rod and main bearings. I've had several
that were within new tolerances after extreme mileages (one at 204K),
so you may not even need to replace the bearing shells. If you don't have
a ridge at the top of the cylinder, all you need to do is go over the cylinders
with a "glaze breaker" (a hone that takes the shiny surface off the cylinders
but removes approximately zero metal) and put in a new set of rings.

What usually goes bad is the camshaft. I've been using the IPD 7001 street
performance cam and been very happy with it, also using their lifter and
pushrod set. This will guarantee the cam a long and happy life.
The way you can tell if the cam is bad is to measure the lift of each valve
from the surface where the valve cover bolts down. They should all lift more
than 3/8". If any don't lift as much you have a bad lobe. This is a VERY
common problem and in my opinion is related to quality problems with the
lifters. That is why I don't recommend OEM lifters.

IPD's lifters correspond to Sealed Power p/n AT-992, originally used on small-
block Chevys, and are shorter than OEM, so they reqire a special pushrod.
If they don't have any (rumor has it that they have been backordered for some
time) I know of a possible source for Sealed Power AT-2071 lifters which are
a replacement for the OEM lifters and use the OEM pushrod. They are longer
and heavier than the AT-992.

Congratulations on your new old-timer. You will find it a little strange
in some respects but extremely safe and durable. You can throw all those
crazy metric tools away, too. Who needs 'em???
--
George Downs, The "original" Walrus3, Bartlesville, Oklahoma