If you have the 5.7L MDS it can run on 4 at times when conditions are correct.
a gm 6 cyl. If you pull it out of a same year s-10 or complatable one it should set right down in with no other alterations
firewall4 - 83 - 72 - 61 - 5front
Size and shape.
That's Fords twin plug ignition system