spark plug thread type, helicoil/timesert info?

[Ken Keith]

Hello,

Would anyone happen to know which kit I need to do the helicoil 
operation to my spark plug hole, on an '88 5kcstq?  I guess if there 
is no kit offerered specifically for the car or plug, then I need to 
know the thread size and pitch?

Any BTDT's for fixing plug threads?  I know many listers have done 
EM studs, but not too many plug threads apparently.

Thanks!

Ken