Slant Six Points Ignition Trouble

Me......beat up Dakota 5.2 run around town, 01 beater unknown big time miles over 200K, big cab Cummins about 140K, and a 2004 GMC with 100K

LOW MILES!!! My lowest mile ride has almost 300k on it! My '84 Suburban 6.2 Diesel has a million miles on it (original engine never out of chassis)...