Hey all, thanks in advance for taking the time to read.
Very frustrating week/weekend here for me as I missed Wheelin' Walla Walla this year bc of this issue.
Car has been running great until about 3 weeks ago when I parked downtown and after lunch had a really sluggish crank. Got home and it sounded as if the rod in the starter was spinning fast but wasnt engaging the crank in the engine. I figured it was a power issue. I had a buddy come over and we changed the starter and the solenoid. Started right up. Last week same issue I thought maybe a battery issue so I kept it on a trickle as the battery was 6 years old.
Friday before the car show cruise went to get gas, had a sluggish crank again at home and then was dead at the pump after filling up. Over 2 hours at the pump I replaced battery with brand new one and changed the damn solenoid AGAIN. It sluggishly started and I got it home. Now dead. Fuel pump primes normally, all accessories work, battery tests perfectly and even the magnet switch in the solenoid is clearly flipping. You can literally hear and feel the switch in the solenoid when you turn the key ignition.
Maybe a grounding issue in the path between the solenoid and the starter? Starter casing touching something it shouldn't? There is just the one big wire from solenoid to starter ��
Anyone have this issue before? Any ideas?

Thank you all.