ACT Sensor drill and tap size

[MarsChariot]

I will need to drill and tap the boss on my GT-40 lower for the ACT sensor. Does anyone know off hand what the drill and tap size is? NPT, looks like 18 thread pitch, and maybe 5/8. Appears the same as the water temperature gauge sensor.

 

[76 bronco J]

hey how's it going....,,,,don't want to hijack the thread ,but just curious about how the GT40 lower is fitting with the "X" heads compared to the performer-289,,,,are you still going to use the M-9439-A50 intake gasket ford recommends or something else ,,,,,

 

[MarsChariot]

hey how's it going....,,,,don't want to hijack the thread ,but just curious about how the GT40 lower is fitting with the "X" heads compared to the performer-289,,,,are you still going to use the M-9439-A50 intake gasket ford recommends or something else ,,,,,

Yep, the GT40 fits like a glove and the M-9439-A50 intake gasket seems to fit perfectly. It is a tad wider, so it covers the intake openings on the GT40 heads much better. But I got a GT40 lower without the ACT drilled and tapped on the number 5 intake runner, so I need to do that before I get serious about bolting it down.

 

[Broncobowsher]

Tap 1/2 NPT for the sensor.