"302" heads

[Mikes270dart]

for anyone that has done it, what size of drill and tap did you use to block off the holes below the exhaust ports.

 

[C130 Chief]

1/4-20

 

[Prine]

5/16 drill bit..to reach clean material...then..Mig Welder.

 

[66fs]

1/4-20

No drilling, Just Tap as above then install a set screw below flush.