I don't where you can find specific info but I can give you a few pointers. First you have to decide how low you want to go. I have a 71 shortbed with 4-1/2 drop in the front and 7 inches in the back. That is about as low as you can go and still somewhat be able to drive it. I did it with 2-1/2 drop spindles and 2" coils. The problems with the 2" coils is getting the camber back straight. You have to take it to a good alignment shop. If you only want to go 2 inches or so the best way is to use drop spindles or lower a-arms with deeper spring pockets. There are several companies out there but I would stick to either classic performance or early classic enterprises. They specialize in the older trucks. Now in the back I used 2 inch blocks between the trailing arm and the axle. I made them myself from a chunck of aluminum but you can also buy them and they come with longer u-bolts. Then I used a 5 inch drop spring to get down the total 7 inches. In order to lower that far though you have to cut the frame and put a c-notch. If all you want to do it lower and level the truck I would recommend drop spindles and 4" lowering springs for the back. there is other things you need to consider when you go as low as I did. I also have a 67 shortbed that is a daily driver. I went cheap and lowered it 2" all the way around buy cutting one coil off the front and making 2" blocks for the back. You do have to break the ball joint loose to do it and then you have to get it realigned to get the camber back in spec. Anyway I hope this info helped you and good luck. Also early classic and classic performance have pictures of truck at different heights to help you visually decide how you want to go.
It's also usually necessary to install an adjustable track bar in the rear to re-center the wheels. It's also necessary to relocate shocks in the rear if you go lower than 5 inches. After 5 inches, the shocks are at such an angle that they really can't work as they were intended anymore. And NEVER cut springs, Drop springs are just too cheap to risk messing with springs that are probably 30 years old and barley doing what they were designed to do. The springs' main function is to keep the tires planted on the road so that you can maintain control under normal AND non-normal driving situations. Cutting the springs on a truck that is driven daily compromises the ability of the spring to keep the tires planted. At around $100 for drop springs, it's just too cheap to not do correctly. Dval
I agree with everything you said although I have been driving my 67 with one coil cut off the front for a year and have never had any problems. I agree it is not the best way to do it but if done right on a non-variable rate spring with proper alignment I haven't had any problems. You are right though drop springs are pretty cheap. If you go as low as I did you might want to go with a drop shock too. They are designed to increase in pressure at the bottom of the stroke to help to keep from bottoming out. Duetch Tech nitro slammers ride half way decent. That is what I have on my 71
