What you are wanting to do takes a lot of work and fabbing. You may or may not find someone who has done all the work. It's going to be up to you to measure rear axle width and determine if it fits... and the steering box to column and the pinion angle and the ebrake and so on.
I may not understand exactly what you want to do yet. Which modern parts you want to put onto the 50 frame. BUT:
It seems you are saying you are using the 1950 frame and the 84 front.
I don't know what this means.
"I heard I can use my front axle with spacers on the 1950 one can I? " which axle is "my front axle" and what is the "1950 one" = axle or frame??
The Stovebolt search function yields this:
https://www.stovebolt.com/ubbthreads/ubbthreads.php/ubb/showflat/Number/1090808
