Oil Pump Gasket

When replacing a big block oil pump, do I need to use a sealant on the gasket?

I assume we are talking the gasket against the block? sealant is not necessary, however I use a thin coat of Hi Tack to prevent seepage. Never use silicone, it will find its way into the oil passage hole...way too thick!

The Mopar Engine Manual says no.

The ”O” rings do all the work.

The gasket is “suspenders on a belt”.

Looking at the other post about bronze gear wear I wonder how much impact if any there is by using no gasket, thin gasket versus thick gasket.
Makes you wonder.

My guess would be little to none. The hex end of the intermediate shaft slides freely down into the pump--it does not (or should not ) bottom out. So regardless of where the pump itself sits, the bottom of the drive gear will settle down onto the top of the intermediate shaft bushing. This is what locates the point where the gears mesh--not the location of the pump.

But that's just me spitballin'...

Makes sense.

I didn't think a sealant was necessary, but when looking for torque specs, the Hayne's manual said to put a thin layer of RTV on the gasket. I had never done that before and I have seen other things in these manuals that have made me scratch my head and go huh? I can see using some hi tack, so I will use some. The Melling gasket kit that I've got didn't come with the large o-ring, just the gasket and o-ring for the neck of the pump.

That is what you need, the two O rings in the pump should be in the pump, not needing to be installed in the pump before installing the pump
I have used Gasket cinch on the pump body and pump gasket to hold the gasket in place while installing the pump, I did not use silicone gasket maker type on the pumps or gaskets
The new Milidon race oil pumps now come with O rings only and no gaskets That has worked very well for me on the last 4 or 5 race motors that I used Milidon external oiling systems on Very Well