55 Bel Air

I am not familiar with this engine. Is it a V or an inline? Does it have hydraulic lifters or solid lifters? Solid lifters, if adjusted properly, can make noise. Hydraulic lifters normally do not, though a slight ticking noise is acceptable if the valves are otherwise functioning well. A lifter might be slightly faulty.

Distributors can make clicking noises at low rpms, mostly from the points opening and closing. The rotor should not be hitting the contacts on the cap. It should clear them by a few thousandths of an inch. Remove the cap and look for evidence of rubbing on tower contacts. Rubbing indicates a faulty rotor, loose fitting cap, or a worn distributor shaft that allows for eccentricity.

Ticking can also be from other things, such as the fuel pump. It isn't always a bad thing, though if you don't know what it is, it could be a bad thing.

I'm curious about the bent push rods. What happened to them? When I first got my car 10 years ago, someone said that I could run the old gas in the tank through the engine. Well, a thick layer of varnish became liquid, and after the engine cooled, the deposits on the valves froze them, which bent push rods and broke rocker arms. Push rods can also be bent from sticking valves or improper timing, where the valve might hit the piston. In any case, it's not a good thing.

Thomas

The 265 V-8 has hydraulic lifters, you will need to pull the valve covers andm, with a feeler guage, adjust the not on the top of the rocker arm.
There are numerous books out about the small block Chevy V-8 about building, racing or just maintaining them. Another thing to consider is the length of the push rods avtivatng the valves. You said that the engine was re-built, but were the pushrods put back in the same location or were new push rods installed, same with the rocker arms. Excessive wear on either will cause a ticking sound if valves are not adjusted correctly, or there is excessive wear on the push rods or rocker arms.