Whos running a 5.9L Magnum ?

Welcome,you will like it. Ask lots of information before you buy parts. www.Magnumswap.com has lots of good information. The skinny is: Mock the engine with headers installed. Some long tube headers hit the truck engine mount bosses.
If runninf new heads,run the E.Q. "CH318B ". (Magnum heads,with a traditional L.A. bolt pattern.
RPM air gap/M-1 single plane work here. Depending on horse power choices,the stock cam core can be reground for a good price .(think Oregon Cams,or Bullitt Cams here) Hughes 1110 vakve spring /matching retainer combination. Over ..520" lift, have the valve guides milled down. A long post,saves some research time.