The 302s sensor was on top rear of the block. So drilling and tapping the intake manifold near center might work. Are you experiencing pinging/spark knock?

 

Well, I did... at least once.

If I'm not completely off base, the knock sensor on a 5.0 is the same pitch/size as whatever NPT as the oil pressure gauge, right?

It's not a bolt thread size... right?

 

I checked with a 1/2” 13 die nut and a 1/2” 13 common nut. The drain plug thread is close but it will not seal and you will not be able to get it tight enough. It would not be hard to make an adapter if you have a lathe.

 

A relative of mine has one, F-150 5.8L, 2wd SB Auto. It has less than 30K miles on it and he purchased it brand new, right here in town.