I just installed a MD75F it has a 4" exhaustelbow ,as this was a repower I used my old exh.system,2" all throughout as the veralift muffler is 2",will this be excessive back pressure?? This is a turbo.
Volvo has some good tips on repowering on their website but they don't specifically address this online. I would ask Volvo but barring that I would install an exhaust system that matches the exhaust elbow.