88 Blazer EGR issues

[firemedicsafd]

I have an 88 blazer project in the works. i am at the point of putting the new EGR valve on the motor. the question i have is which orifice do i put in place. My motor is a 79' block, 88 TBI intake, 88 body and wiring harness. everything else is being connected like the blazer is a stock 88. the part instructions gave me " OE stamping number" to cross with the new part washer to put back in. if the stamping number is from the block... can anyone give me the number for an 88 block so i can match that to a washer and put it in. Thank you very much!!!!