can anyone tell me about casting # 25534351c with a IM4C above it

they r the vortec bowties with the vortec inscipted in the head i am trying to figure out witch casting i have

25534351c is a 175 cc intake 65 cc ex bow tie vortec head. check the last number on your head and see if the 0 is a c .large port head is a 371c.

25534351c is a 175 cc intake 65 cc ex bow tie vortec head. check the last number on your head and see if the 0 is a c .large port head is a 371c.
its a c

does the c make a diff in the casting

i went and looked at 3 sets of these heads today. all of them ended with a c. one set was new in the box and the box had the right part number. my info lists the last number as a 0 . all 3 sets of heads looked like they ran out of room and choped of the end of the 0 and made it a c . my info may have a typo on the last number too. hope this helps ,

i did a little more checking and it seams my info is a typo. the last number is a c not a 0. the heads are killer , you will love them !

what i am trying to figure out is what series they r i know the except the larger cam without work and that they have the larger valves and screw in studs