boat backfires out of carb at 3,000 1993 5.7 alpha one gen 2

[riverboy460]

did compression test. 1 and 2 were 170 psi and 3-8 were 175. replaced plugs and wires and cap and rotor. had put a new thunderbolt iv ignition module in 2 months ago because of no spark. after i tuned up the boat i ran it on hose playing with throttle and getting to go 3,000 rpm and higher before missing. ran it on hose for 5 min or so and motor stalled and wont start my timing light indicates no spark again. timing was accurate. what can it be other then the pos ignition module. and how can i replace with sumthing better. aka aftermarket mechanical advance electronic distributor with no further problems