Performance parts?
Summit Racing is where i found everything i want to get to beef up my motor and for the 2nd part of your question yes depending on what your going with. Your ECU will only recalibrate so much as far as cams go. GT-40 heads, cam, and intake are a really good start off a explorer.
Bronco graveyard has allot of axle,engine swap kits and off roading stuff on there give them a try here is the link
for engine parts what hee said summitracing.com
http://broncograveyard.com/
http://broncograveyard.com/

