I was out helping someone, and they had this old '76 Chevy C60 bus. Curious, I had a look inside and was reminded about old truck 5 speeds. However, the first gear was marked "L". I've heard of trucks all the way back to the 40's having 5 speeds, but have any of you ever experienced them? Like that bus, is it more of a regular 4 speed with extra low 1st?