TPI cylinder heads??
 

Can anyone who has a TPI 350 tell me the 8th digit (from the left) of their vin. This would greatly decrease my chances of mistaking a 305 for 350? (yes i know the bore is different and I would like to avoid memorizing engine codes, unless there is a pattern)
The reason I ask is I want a pair of these cylinder heads for my older chevy motor. From my understanding *most* of them bolt right up to first generation small blocks and have more efficient/higher compression cumbustion properties than the 186's I'm currently running.