vin numbers F and S

[Gerald66]

hi i am new to this site need help with vin numbers.
what is the difference with vin f and vin s. I have a 1996
k1500 6.5td it has vin s

[94K30]

S vins are in 1/2 tons, with EGR vavles, the heavier trucks did not have the EGR, they were coded with an F motor. The intake is the diference... with or without EGR

[Gerald66]

thanks for the info