General LSX Automobile Discussion - what engine is this

i posted earlier that i had a 65 gto with a 455 in it on the block just below the head on the passenger side are these numbers 0386343 just below that in the middle of the numbers is y9 i know the 455 is not original that is why i'm trying to find out what year it is so i can order partsi'm not positive it is a 455 that is what i was told when i bought it he said he thought it was a 455 hd and that it had 400 heads on it so any help i can get would be appreciated thank you

i posted earlier that i had a 65 gto with a 455 in it on the block just below the head on the passenger side are these numbers 0386343 just below that in the middle of the numbers is y9 i know the 455 is not original that is why i'm trying to find out what year it is so i can order partsi'm not positive it is a 455 that is what i was told when i bought it he said he thought it was a 455 hd and that it had 400 heads on it so any help i can get would be appreciated thank you


good ole bop stuff...

I cant remember the differences to tell you anything other than my buddies 71 bird with a 455 was/is a BAD mofo

A y9 block is a 1974 455 ci.

http://www.gmclassicmusclecars.com/pontiac-block-s.html

thanks i appreciate everyones help