1998 blazer motor type...W??

what different type of motors are there in a 98 blazer with the 4.3L. there is W or V

the 4.3 in the 98 blazer/jimmy/bravada has a W as he 8th digit in the VIN. the other 4.3 for that year had a X as the 8th digit in the VIN and was used primarily in the s10 pickup. only difference is the computer tuning.