To my amazement, i cannot find a tightening spec in the factory service manual for the engine’s coolant block drain plug. Looked under both Engine and Cooling System sections. A search here on Sl 6.org brought up nothing.

This is for a 1981 hydraulic lifter 225 Slant 6. Here’s the plug: I’m measuring 1/2" O.D. Head mates with a 9/16" socket. Didn’t have small enough pipe fittings to try and fit, but it looks like it might match a 1/4" I.D. NPT pipe.

Apparently last time it was out i just winged it when i put it back.

Anyone know the proper torque?

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1981 B-150 short Van, stock 225, California emissions package, Electronic Spark Advance (digital Lean Burn), Non-feedback Holley 1945, AT
Driven for economy, not for speed.

I thought that those were pipe thread. If it is, I don't think there is a torque value for it.

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-MattMan
LEANED & MEAN

I've had lots of those out, never torqued one w/a torque wrench yet.
And yeah they're pipe thread
I put petcocks in that hole like what's on the bottom of the radiator