Rebuild questions on a 74 8.75SG diff

My Challenger- I know, I know- developed a "crunch" at the end of the season and I'm going to see why. It's a cone style SG and I'm leaning towards a clutch type or A/M unit. I'm shopping for the best bang for my buck for rebuild parts, gears (I'm going to build a second carrier that I can just load into the housing rather than deal with the oem one.) replacement SG, either oem or a/m. Can anyone offer some direction here? Thanks in advance for any advice that helps! I'm a member on an E body forum, but being an old A body guy I've also noted the increased amount of knowledge and parts here regarding mechanical matters, so forgive me boys.