I think i have a 255 hp 1967 GTO I am look for any info so i can tell for sure..Head #'s what every.

If it's only got a 2bbl carb, then it's a 255.
Engine code will be XL or XM.

keep these sites handy for reference...
[www.1967gto.com]
[www.gtoheaven.com]
[www.gtoalley.com]
[www.oldride.com]
[ultimategto.com]