I recently bought 1995 Chevy C2500 6.5L ext Cab Regency Conv 2whl Silverado w/130k AT. Changed oil, air filter and fuel filter. Noticed between 48-50mph it'll hesitate stay running, but sputters. It'll clear up a little but as I accelerate to 65mph it continues not constant. Did I leave add trapped in when changing f.filter. It starts easily runs good at idle up to condition, doesn't spew black or white smoke. Will do PMD relocate, need to change GP's check Injectors, Fuel Pump & lift Pump, any idea's appreciate it thanks