I have a friend who purchased freeze plugs for his Chevy only to find they thread in. He wants to sell them but first I must ask are they applicable to my truck and are the diameters the same?

 

The Ram's are press in, I just had one sitting around here. Dang it! can't find it to measure it.

 

all freeze plugs are press in. that way they in the event of a coolant freeze, they can push out to release pressure. if they were threaded, then they wouldn't do any good.

 

maybe he's referring to the bolts in the block next to the freeze plugs then....

 

The "threaded" type could be the universal replacement type used for a damaged hole or in a hard to reach location like near a starter. They are made with a captive nut/washer and bolt that squeezes a rubber center section.

 

Some race engine builders use pipe plugs instesd of the original welch plug. Some also use brass instead of steel.

 

what happens if the engine freezes up ?

 

Im pretty sure not a lot of race engines will see cold weather.

 

The "proper" term is "core plug". They are needed because of the sand casting method used manufacturing the block.

A few blocks do use threaded plugs. Some performance blocks have threaded plugs for "strength and security". Brass is used in marine applications.

 

If it gets cold enough it's going crack the block any way, freeze plugs wont save it.