i have 01 dodge neon with a 02 swap in it the first day after swap ran like bat outa hell but started get some bad back fireing and stalling but i was out so i powered thro i should of known better but it let out this loud asf pop then after started acting like dragster were it would just wah ta ta ta ta in gear but bearly pull like dragsters when there fixing to launch so figured out blew the head doing 120 on hwy changed it all good but now i can start it fine haul *** or drive right for about 5-8 mins then it will start the poping again and shortly after will just die ill hit nutrel turn key nun no spark ill pull over pop hood check for pressure in rad hose bleed pressure if any some times it will start up after but not always if no it 89% shot it will fire up if i disconnect a spark plug when i do and it starts it will idle fine ill get shocked puting plug back on drive 1-3mins and repeat tell i let it cool i change thermostates it dont get hot have a temp gauge never gets over 189 rad fans stay on flushed cleaned radiator any ideas

 

Record set for longest run on sentence ever. And you lost me at doing 120 on a public highway.