First generation matched pair of "Double Hump" cast heads (05-24-'62) with larger volume (64cc) exhaust ports and intake ports (172cc) as opposed to 62cc exhaust ports and 160cc intake ports on the regular 461 castings.

The 461X heads were cast from 1960 – 1963 only and were mated to the 327c.i. and some 283c.i. blocks. They were factory fitted with 1.94" intake and 1.50" exhaust valves. It was not uncommon to have these heads machined to accept 2.02 intake and 1.60 exhaust valves to achieve even more performance. These heads were likewise upgraded for the larger valves and are threaded for screw-in studs.

The 461X heads were cast with an "X" on the underside of #1 or #8 exhaust runner depending on which engine bank the head is on (see photo). Some of these heads were factory fitted on 327c.i. engines, which had Rochester fuel injection (thereafter dubbed “Fuelie” heads) in a limited number of 1963 Corvettes, producing 340+ bhp.

Wonder if these heads came on your car? Here's some research... “Keep in mind that Corvettes were not the only models to get these heads. They were also on 300hp/327c.i. ‘62-‘63 full size cars, a fair amount which were built. If they were a Flint head, there is no way to know if it was originally installed on a pass car or Vette engine. But if it’s a Tonawanda head, then it was a pass car.” (Source: Tom Parsons, Corvette Forum 12-03-2009).

Produced for only four years, these are becoming increasingly very difficult to find. Safely stored in my shop for over 30 years as a spare set for my race engine, I had these magnafluxed and hot tanked and found no evidence of any gasket matching or porting done to them. However, the push rod holes were enlarged to accept guide plates for the push rods. For obvious reasons I cannot warranty them as they are used. Buyer to pay actual shipping costs. Free local pickup also available in SW WA and NW OR.






Cast "x" on the exhaust runner. Not stamped.

Double hump casting

Casting number



Thanks! Doug

 

I love to stumble across interesting stuff like this on the forum! Here's hoping they go to a good home. I'm sure there are plenty of Vette guys who'd love to a set!