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454 drain plug size
Posted: Feb 9th, '24, 12:25
by pschauss
I'm thinking replacing the drain plugs on my 454s with hose bibs to make it easier to drain the coolant. What is the thread size?
Re: 454 drain plug size
Posted: Feb 9th, '24, 13:12
by JeremyD
1/2" -20 thread
Eddie Marine makes a nice oil drain kit
https://www.summitracing.com/parts/edm- ... cgQAvD_BwE
Re: 454 drain plug size
Posted: Feb 9th, '24, 21:07
by pschauss
Not NPT?
Re: 454 drain plug size
Posted: Feb 9th, '24, 21:53
by Tony Meola
Peter
Why not just pull one and just get it matched up.
Re: 454 drain plug size
Posted: Feb 16th, '24, 13:37
by S Ritzert
1/4" npt unless its been tapped to a larger size. about the mid 90's mercruiser went to a blue plastic drain plug, I'm not certain on that thread pitch, but the brass that goes into the block is still 1/4 npt. Volvo also used a blue plastic plug that is a different pitch than mercruisers about the mid 90's. regardless, the actual thread into the block is 1/4 npt.