I bought a 74 truck and it has 2 in Rancho lift springs. I want to put them on my 81. I've been told they will work except for the fact an 81 has an 18 mm bolt and the 74 has 15 mm bolt and I'll need to get bushings to accommidate that. Has anyone ever tried to do this and know if it will work or not? The 81 is my daily driver and I've got to be able to do it all in an afternoon. Can't have any surpises. Thx