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storm9c1 · 08-23-2016, 02:58 PM

Yep, port in the heads are good, but for an electric fan switch at 180 degrees, I'd prefer an intake port. Fans may run too much in the head port. I'd move the gauge to the head port and the fan switch to the intake port if you can. I prefer a gauge on the head port because it will let you know MUCH sooner if you are about to overheat. I like having an earlier warning.

For the thread sizes on the head ports:
Vortec heads: 3/8" NPT
Older 60's/70s heads: 1/2" NPT

For clarification regarding the square plug, you want to use the 3/8" drive of the ratchet (or extension) with no socket attached. The square drive should fit right into the plug.

08-23-2016, 02:58 PM	#10
storm9c1 * That's interesting * Join Date: Oct 2008 Location: Pittsburgh, PA Posts: 2,772	Re: unscrewing plus at the end of heads Yep, port in the heads are good, but for an electric fan switch at 180 degrees, I'd prefer an intake port. Fans may run too much in the head port. I'd move the gauge to the head port and the fan switch to the intake port if you can. I prefer a gauge on the head port because it will let you know MUCH sooner if you are about to overheat. I like having an earlier warning. For the thread sizes on the head ports: Vortec heads: 3/8" NPT Older 60's/70s heads: 1/2" NPT For clarification regarding the square plug, you want to use the 3/8" drive of the ratchet (or extension) with no socket attached. The square drive should fit right into the plug. __________________ Tom Chevy by day... 1969 Chevy C30 Rollback Tow Truck -- 383 stroker, 4L80E 2011 Chevy Caprice PPV 9C3 6.0L 1995 Chevy Caprice 9C1 1994 Chevy Caprice 9C1 #3 1995 Chevy Caprice Wagon #2 1995 Chevy Impala SS Mopar by night... 1969 Dodge Charger 1972 Chrysler Newport 2dr Hardtop (27K miles) Plus others...