[Mike C]

First of all, thank you for putting the effort into searching some before posting! It is very unfortunate that ECE hasn’t been resurrected after their purchase by Holley.

Switching to disc brakes means a 2 1/2” drop spindles and then either a 1” or 2” drop spring. On my ‘69 I did use the ECE kit with 4 1/2” drop in the front. Spindles and a 2” spring. My truck is a leaf spring C10 so a DJM flip kit netted just over 7” drop in the back.

I run a 235 55 17 tire in the front and a 275 55 17 tire in the back and the truck sits very level. The swap to 17” wheels (or maybe 18’s now because of tire choices) one of the absolute best mods to my truck. It allows plenty of tire height with a somewhat reduced sidewall as well. Your wheel tire combo dictates the stance as much as the spring combo. Math says the fronts are just a 1/10 over 27” tall and the rears a 1/10 under 29” so there is 1” of rake built in to the system since half that height above axle centerline and half below.

I would probably do a 5” spring and a 1” block in the back for a 3 1/2” front 6” rear drop if running same height tire all around. The block allows you to have an inch of adjustability if it is too low for your tastes.

I wish I could tell you who makes the best kit anymore, but I like doing business with Speedway so that’s probably where I would start.