Hi all well I need size of fitting for autmeter Oil pressure gauge with brass hose and for water housing on the back. these are for 76 13B 4 port. I need to purchase these and engine will be ready to start shortly thanks.

 

tap the back of w/p housing with 3/8 pipe.

 

If you figure out the thread pitch on the back of the water pump housing, let me know. I'm pondering this same question but for my t2 motor. I know the Autometer piece for both the water and oil is 1/8th npt. Autometer supplied 2 adapters with my water temp gauge but both are standard. You could retap it or try and find out the appropriate thread pitch and find the adapter.

I bought the adapter for my oil pressure gauge from http://www.mcmaster.com/
they sell everything there.

I don't remember the thread pitch for the oil pressure hole but it was bspt threads. I found the appropriate bspt to npt brass adapter. I hope I can do the same for my water temp.

 

Drilling and tapping the back of the water pump housing is the easiest and best way. Took mine in to a local maachine shop and they charged me 20$CA for it. Thats without me even shopping around so its fairly cheap to do. You might want to order some new gaskets if you want on removing it though. It should be too much you only need 3 of them:

Water Pump gasket
Water Housing gasket
Thermostat Gasket

And if you still have the original thermostat another 10$ish will buy you a new mazda thermostat.

 

I have these two links saved for quick reference for easy to order conversion fittings, but I believe the first one is meant for the oil pressure gauge fitting, because of its weird size.

http://www.pegasusautoracing.com/Pro...asp?RecId=3142
http://cgenterprises.com/magneticdra...hread_bspt.htm

 

Just go to summit, or a local speed shop to buy fitting from there ... BUy only NPT as its the easiest way to adapt things and find and usually cheapest.

 

OK, anyone know the thread pitch for the stock water temp sending unit that screws into the block? It might be easier for me to just use that and forget about keeping the stock gauge hooked up.