Slant six head numbers

Huffpullers said
The numbers on the right side of the head on my slant six read G 225 T 7 1 can someone shed some light on these numbers. Trying to find out the manufacture year and if it’s a solid cam or hydraulic

That's not on the head, it's on the block deck surface. It means it's a 225, other than that, I don't know more. @slantsixdan can tell you for sure.