5/8 by 11 pitch

 

I dont see no threads in the holes.I think I need freeze plugs.

 

The ports on the backs of the heads? They are the size of the spark plugs (which somebody informed me of).

 

Are these the plugs???

http://store.summitracing.com/defau...51400265&Ntk=KeywordSearch&DDS=1&searchinresults=false&N=0&target=egnsearch.asp

Trickflow part number 51400265, these are 9/16-24.

 

yup

 

9/16-24 is the threads on the inside of the inserts. The holes in the heads are still 5/8-11.

 

Ford makes a plug kit too... its like $9... the guys at the counter might take a while to find it, but its out there... just make them look.

I have used them several times when removing the smog equipment from 5.0s.

Good luck.

 

spark plugs worked for me. I had some carbon build up so I stripped the threads on the first spark plug, but they are only like $2. Just break off the end, you can't see it anyway.
The guys at Ford had no idea what I was talking about when I tried to get the plug kit, but I know they have it because I've seen it.