The 270H head has a casting number of 2193417 and was only made in 1951 and
1952. The casting number should be visible on the top surface of the head on
the driver's side, or possibly under the rocker cover in one of the spring
pockets. I don't think there is an "H" in the casting number
This head has more performance potential because of the bigger port size,
but requires special domed pistons to make compression. It's also prone to
cracks and leakage because of the port design - that's why GMC only made it
for a couple of years. These facts make it less than "desirable" in my
opinion. But, it was sought after by racers because of the improved airflow.
Without a performance cam and more carburetion, the small port 228/248/270
heads are actually better for normal street operation on a GMC.
Jack
www.inliners.org
----- Original Message -----
From: <JMungon@aol.com>
To: <oletrucks@autox.team.net>
Sent: Friday, October 18, 2002 10:58 PM
Subject: [oletrucks] 270 gmc engine ident..
> <PRE>i have located a 1954 gmc 270 truck engine complete...is there
anything
> special about them to check.....could the desirable "H" head appear on
this
> engine and where do you look for the "H" casting letter....thanks in
advance
> for the help..jerry
> oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
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