Took me a good 5 minutes to find this for you...So this is a good read posted a few weeks ago or so..
Pretty much in a nut shell, you can not change your IC on leaf spring cars, unless you have more holes up front for the front eye of the springs..
https://board.moparts.org/ubbthreads/show...part=1&vc=1

[color:"red"]65 Hemi Belvedere coming soon [/color]
[color:"#00FF00"]557" Indy engine 1.07 60ft 144mph in the 8th 2100 lbs package [/color]