So i have a 1994 dodge ram 2500 v10 magnum sport, I plan to take the engine from this and put it into an older challenger. I never have heard of anyone doing this before, and wondered if anyone had some helpful knowledge on this.

 

I have seen new style Hemis in older cars, but not a V10. It may be too long to fit between the firewall and core support. I believe that the older V10 is different than the later Viper engine, don't know what difference that will make though.
I have seen a one off 08 Challenger with a Viper V10 built by SRT just for the heck of it. It is unable to be sold since it was a pre-production car destined to be crushed