I pulled a pair of 461's off a 68 Impala many years ago and took the set of heads into a local machine shop and had them checked for cracks, etc. at the time. The machinist told me they were unported, unmolested heads. With a date code of I 11 4, or Sept. 11, 1964, 65's I would assume, and according to Mortec.com, 62cc's. Does that mean they are 1.94/1.50's or 2.02/1.60's??? I would like to put them on a .030 over '62 327 using a stock '67 spread bore intake and quadrajet. I know the engine came out of a '62 Impala with the original 4 bbl. square bore intake. If these heads are 2.02's, any idea what would be a good cam to run? Any help would be appreciated. 64elkynss

they could be machined for either 1.94 or 2.02 intake valves. the same casting was used for both, so you can't tell from the casting number which they are. It is really very unlikely that they're 2.02 because thoise were used only on a few hi-perf and Corvette engines. those were a tiny percentage of the overall production. The type of engine you're building it won't make much difference anyway, go with what you're got. Those heads have soft iron valve seats so you're taking a pretty big chance spending any real money on an engine with them unless you have the hardened exhaust valve seats installed. You might get by with it, you might not.

Heads are getting new valves, etc., before the install. I'd figured it might not matter for performance since it's basically going to be cruiser/mild street, not wild, but just wanted to make sure. I guess I'm going to have to take them to another machine shop (other one closed a year ago) and get them measured so I don't get the wrong valves. 64elkynss

My virgin -461's, (except for studs), have stock big valves in them and you can see and feel the factory plunge cut GM made to unshroud them so they will breath better.

Mine measured right at 66.0 and 66.+ cc's.

I always figured that they measured like 62 or so with little valves and 64 or so with medium valves but don't know for sure...

pdq67

You sure 461s ever came with 2.02 intakes.

they could be machined for either 1.94 or 2.02 intake valves. the same casting was used for both, so you can't tell from the casting number which they are. It is really very unlikely that they're 2.02 because thoise were used only on a few hi-perf and Corvette engines. those were a tiny percentage of the overall production. The type of engine you're building it won't make much difference anyway, go with what you're got. Those heads have soft iron valve seats so you're taking a pretty big chance spending any real money on an engine with them unless you have the hardened exhaust valve seats installed. You might get by with it, you might not.

Not just Corvettes. The L79s all had 2.02 valves in 461 heads.

You sure 461s ever came with 2.02 intakes.

Absolutely, L79s and L76s all had them.

461 and 291 SBC Head Castings 66 and 64 CC's respectively came with 1.94/1.5 valves and pressed in studs found on 327 Engines. These heads are very desirable because you can put in the 2.02/1.6 valves and keep the Valves Hight in the combustion chamber as compared to re-finshing the sunken seats of a 2.02/1.6 head. The Pressed in stud can be replaced with Scew in and the Valve Spring Pockets inlarged to 1.439. Grumpy Jenkins has fantastic Porting Technics for these heads and a very interesting read. The only problem with these heads is that the Exhaust Seat or not hardened for non-leaded gas, in which case MTB or additives should be used or have a harened Exhaust seats installed when doing the valve job.

Considering the work and costs related to make these heads competive, I would suggest you go Vortec and buy the Vortec Intake manifold. ToDay the Vortec is about the best OEM flowing head GM has to offer without going after market and cost considerably cheaper then preparing either of the camel hump fuelie heads.