Whutt Is Location for Head/Block Stampings

needing to decipher whether or not the heads on this 318 have been changed for the better since ive heard that original LA heads didnt 'breathe right'.these heads look super clean under the valve covers and the metals are a reddish brown not rust but shiny.No sludge ....clean unuff to eat off of. any ideas as to what heads fit the 68 318? any ideas as to find out what tranny is in this thing? Like where do i find the indicating brand/type of automatic trans it is?its a 3 speed Auto on column...i dunno anymore :shakehead

(stamping on engine'Block) is PM318R 23281316.
VIN: WH41F8G182393

It's a 318 car then. The other topic was titled 440 but I guess you meant the car line. 440, 500, that sort of thing.

It's a 904 trans.

wuz still wunnerin where the stamping for the heads may be,,or do i gotta pull the valve covers off?? these heads look 'new'specifically under the valve covers....GOOOOOOOOOOO Buckeyes 28 to 14 ohio leads @ half