need help with a motor

can someone find out what type of heads these are and year from the head numbers under the valve cover. one is 1231786 and the other under there is A 20, help please

 

The 1231786 is a 1970 455 head. Don't know what the A 20 is.

 

A 20 is the date code of the head...January (A) 20.

 

thanks

thanks guys. the other ? is what do you think they are worth ? also have a 430 motor in a 67 wildcat. not running, cleaning up the yard

 

Here's the website that has all the casting numbers. If the 430 heads are big port heads, they'd be worth $$$$$, to a point. The sale on those aluminum heads is mighty tempting to many.

http://www.atlantabuick.com/CastingNumbers.htm

 

I have them on my page too...

http://mywebpages.comcast.net/jholthenrichs/weightsn.htm