Hello Jay of the previous racing Mainship fraternity,
Two other things to consider for Mr Ryan,
The copper tube and valves for the 78' is caveman, and considering what replacements would cost replacing it all would make a good weekend project. Just sh_tcan all that old garbage and replace with new copper and ball valves. I can't tell you how many times I chased down an air leak in that old spaghetti across the aft bulkhead.
If you have a Racor filter the round diffuser in the bottom of the unit where the fuel comes out and spins is hollow and there's a metal ball inside that is probably designed to distribute the fuel evenly. This is raw fuel as it comes from the tank and in my olde '78 the cavity where this ball lives was completely blocked up with the black goo. The bottom of the diffuser just unscrews to give access, check it out.
As previously mentioned, a professional tank cleaning may be well worth the cost. Wait until you have about 1/4 each tank. The guy that did mine had a high pressure nozzle on the return line that caused the hose to whip around inside the tank like an angry snake to stir up the sludge.
Also as previously mentioned I usually carried a 5 Gal Jerry can and had the tubing handy to quickly plumb it into the fuel system in front of the primary filter. Came in handy a couple of times.
Replacing the pick ups is also a good idea, although a little more involved.
My olde MSI stopped running a few times. Every time was for a fuel problem, it was never an engine issue except for throwing a belt which was my fault for bad maintenance.