ATC90 cylinder head questions?

[ram]

i have a problem the person that had the bike before me like stripped the spark plug hole and then tried to re thread it himself now when i put the spark plug that is needed (90 cc)-( NGK D8HA) it dosent want to thread and it goes in almost not touching anything. I thought i had it in on 1 spark plug felt snug when i started to crank it the spark plug blew out. Is there any other spark plug that i can use for this slight bigger opening? if not can a 110 head go on my 77 90? And maybe does anyone have a extra head/motor that they want to get off there hands. thanks

[greenhuman]

You can re-tap the head to take a larger plug. Just make sure the new larger plug is a short reach.
A 110 head will fit the 77 90 as well.