1963 327/340 shp

[RICHARD CHARLES]

i own a 1963 roadster the block is dated ( D 12 63 ) I need a set of heads .what would be the correct #s to match the block ? 461 X & what would be the correct dates ? how far apart can the head # s be to be correct ? THANKS NCRS member

[Rick A.]

Re: 1963 327/340 shp

"camel hump" 461X heads would be fine - dated up to 6 months prior would be fine

[Joe C.]

Re: 1963 327/340 shp

Richard:

Are you sure that the cast date on the block reads "63" and not just "3"?
I have a pair of 461 "double hump" heads from a '63 Corvette. If you are interested talk to me "off the boards", and I'll go get the dates for you.

Joe

[Rick A.]

Re: 1963 327/340 shp

Joe,

good catch! should only read something like J113 not J1163! my bad! I was just trying to get a response out to Richard so he could do some research.

[Duke W.]

Re: 1963 327/340 shp

The head casting number and date code are under the valve covers,so they are not judged. The judges can only look for the external visual cues, which would be the double hump symbol and no accessory bolt holes up front. I believe either 461s or 462s would pass judging muster, so there's no reason to have a "correct' casting number/date code unless you want the heads to appear "correct" when you take the covers off to adjust the valves.

Duke

[RICHARD CHARLES]

Re: 1963 327/340 shp

so what is the differance in yhe ( 461x & 461 ) RICHARD CHARLES

[Mike M.]

Re: 1963 327/340 shp

on the 461X heads, the camel's humps are squared off . on the 461's the camels humps are convex shaped when viewed from above. you shaould also note that the tonowanda cast heads of the 50's and 60's were cast dated with a double digit for the year in question, ie xx-xx- 57 for a 1957 cast tonowanda head whereas the flint( and hence vette head) were cast dated with a single digit for the year( ie, xx-xx-7 for a flint cast 1957 head.). note also that it is possible to differentiate a flint vs tonowanda head WITHOUT removing the valve covers since the flint camel humps were broached smooth and the tonowanda were rought sand cast on at least one of the head's ends.mike

[Joe C.]

Re: 1963 327/340 shp

Duke:

You are absolutely right, but if you don't already own them and are shopping for them, then you might try to see what turns up. When I bought my 461's for my '65, I got lucky, and found a pair that had the right dates!!! I only looked for 2 weeks, and wasn't going to knock myself out any longer than that. Sometimes, you just never know.
Also, Richard doesn't need the "x" head. The ordinary "461" would do just fine, thank you.
The 462 is a slightly superior head, because of a change in the spark plug location, but I am not sure if there would be some very subtle differences in the configuration of the visible areas.

Joe

[Joe C.]

Re: 1963 327/340 shp

Richard:

The "461x" heads had larger runner volumes, and were designed to breathe slightly better. They were also installed on some truck motors out of Tonawanda.

Joe

[RICHARD CHARLES]

Re: 1963 327/340 shp

AM I CORRECT IF I SAY THE VAVLES IN THE 461X 461 ARE THE SAME SIZE ? RICHARD

[Joe C.]

Re: 1963 327/340 shp

Richard:

I believe that they are both 1.40"/1.92"

Joe

[Duke W.]

Re: 1963 327/340 shp

Depends on the year. Prior to 1964 all 461/461X heads were ground for 1.94"/1.50" valves. For 1964 SHP/FI versions got 2.02"/1.60" valves.

Duke

[William C.]

Re: 1963 327/340 shp

There is another change between the 461X and the regular 461 casting that is a dead giveaway without removing the heads. The area where the valve cover seats is perfectly straight along the outside of the casting on the exhaust side for the X casting where the regular (later) 461 has a "bump" around the holes for the valve cover hold-down screws. Just another small judging secret learned "through the years" The X heads were used at least thru the first half of '63MY, I don't know exactly when the changeover occurred. Racers destroyed a lot of X heads through the years.

[William C.]

Re: 1963 327/340 shp

Duke, '64-65 were not "X" castings