which cam and converter for my setup

My buddy who is 73 years old has been collecting mopar junk for years. Its a 8 3/4 out of a 69 charger or something. Yeah the perches are alittle bit wider, but nothing a torch, grinder and welder cant fix. I found a guy on the internet that had a 3rd member that was 3.91 suregrip for $250. I got the valiant from my buddy also. Its a slant 6 car. He had a 72 also with a 318, but it had been wrecked in the front. But I'm using it for parts. dats how you do it!