Asking if anyone know the size of the drain plugs for my 1973 302 motor?
I did notice that my drain pkugs are not the same... The treads are pipe (Npt) but asking what size...
Im thinking 1/4th and 3/16th but wanted to check before I go purchae multiple size plugs and then have to return them
Thx
Billy

 

Just ask one of the counter guys at any big box parts supplier. They usually have them in stock.

 

I don't think any engines have NPT threads on their drain plugs.

 

If they don't require a gasket they are pipe thread. I don't even come close to knowing everything but I do know some engines use pipe threaded plugs but I don't recall any Fords that do - maybe the old gas-fired Super Duty? (401, 477, 534 c.i.) If your's has pipe thread plug(s) it could be someone installed them after stripping the pan threads.

 

That would be my bet too.

NAPA shows a '73 Truck motor's plug as a 1/2-20 straight thread.
Drain Plug NOE 7041918 | NAPA Auto Parts

But it sounds like your pan has the front and rear plugs? Isn't that a later model 5.0 thing? NAPA shows those as metric, which may explain why someone used pipe plugs.
Drain Plug NOE 7041036 | NAPA Auto Parts