I have two Thunderbolt IV distributors W/ V8-24 modules and harness. $150 plus shipping for each set up. Also have a spare V8-22 module W/ harness for $50 plus shipping. Please PM me if interested.
Check the Module. Happened to one of my 500 HP's last year. Was doing the same thing that you are discribing. I changed plugs, wires, distributor cap/rotor, distributor pick up, etc until I figured it out. It needed a tune up anyways.
B.J.'s Trailers
5940 Hwy 109
Lebanon, TN 37087
866-532-1176
They are just east of Nashville. Take I-40 east to Hwy 109 North. Go about 10+ miles and they will be on your left. I have used them for parts on all my trailers. Very
resonable and helpful.