What size are the hose pipe and temp sender holes in water pump housing?

[bull]

I assume they're all pipe thread (esp the two pipes ) so can someone tell me what size the holes are so I can get the correct taps? The corrosion inside makes it so the pipes only go in about 2-3 turns. Looks like the heater hose fittings measure 1/2" in diameter and the water temp sender hole looks like 3/8" but I'm not sure if that's the tap size. Thanks.

[John_Kunkel]

Pre-'70 BB hose nipples are 1/2"-NPT, the factory temp sender is 1/8"-NPT.

'70 and later has two size hose nipples, one is 1/2" and the other is 3/8".

[bull]

Pre-'70 BB hose nipples are 1/2"-NPT, the factory temp sender is 1/8"-NPT.

'70 and later has two size hose nipples, one is 1/2" and the other is 3/8".

Thanks. I figured out that the big ones are 1/2" today and got them tapped and was thinking the sender hole was 1/8" but still wasn't quite sure. I borrowed the 1/2" tap from my brother and a buddy is going to lend me the 1/8" tap tomorrow.