Help Identifying Heads and engine

I have a set of heads I believe to be 327 double humps but I'm prolly wrong here are the pics and the numbers from what I can read are
GMT 21T 854434 82O07 the numbers my be a little wrong but tell me what to look for and I'll go look

http://img.photobucket.com/albums/v108/Sile1/DSC00184-1.jpg
http://img.photobucket.com/albums/v108/Sile1/DSC00185-1.jpg

http://img.photobucket.com/albums/v108/Sile1/DSC00186-1.jpg
http://img.photobucket.com/albums/v108/Sile1/DSC00187-1.jpg

also I believe this to be a pontiac I believe 70-72 acording to the 400 on the block but feel free to correct me pics are below and here are numbers I have found.
8799914 , 400 , GM-5 D N and d280 the number are all on random spots on the block I couldn't find any others but then again I dont know were to look and it's a complete engine.
http://img.photobucket.com/albums/v108/Sile1/DSC00180-1.jpg

Those are 305 heads, not 327 heads. Not even close!

Most double hump heads do NOT have accessory bolt holes on them and have (last 3 digit) casting numbers such as 461, 462, etc. 492s are true double hump heads with 64cc chambers similar to the 462 heads, and have the accessory bolt holes. The 434 heads you show are from '76-'77 305 engines. You can look up information such as this at www.mortec.com ...

ty for the info on the heads