1993 f25o 7.3 factory turbo is it better to remove the filter holding unite off or can i work around it when doing the return lines im getting brave now that i did the clutch and the ac everthing came out great i got a return line kit from a company out off corpus christi i got diesel smell inside cab where can i go wrong what or key points im getting around in 1951 1/2 ton chevy had it for 30yrs good ranch truck i dont want to get air in system that is my worry