Found the source of the clack.

Bearings, bearings and bearings.

Main bearing shot. Spun #8

others worn.

crank is toast.

came close to trashing this block.

Apparentlly someoneone of the PO`s has been in this motor.

some of the rod bearings were installed improperly.

took some photos will try to post soon.

off to machine shop today.

Sorry to hear that.
Hopefully, it is rebuildable.

Block is re-buildable.

However, some one decided to put Big block valves in the small block head.2.06 intake valves. why would someone do that?

Any way I got lucky .My machinist has a pair to match mine.$300.00

oh well it`s only money.

I did find out though that I have 4 bolt mains for this block.

some one in the past tried to build up this motor, but i don`t think that knew what they were doing.

Think seriously about the GMPP ZZ-4 crate motor. It has a good warranty and comes complete with intake and HEI distributor and runs beautifully with the Q-Jet. 355 HP, and gobs of torque. A friend of mine has run one in a circle track car for the past 2 years without opening it up. They are about the best performance bargain for under $4,000.00. Carl Black Chev. in Nashville gets about $3,800.00 for them.

I run one in my '78 and am tickled with it.

Dave