I just went through this with a 038 . they have a 038 av, 038 super pro and a 038 magnum II . I got mine from ebay with no tags anywhere. so i pulled the exhaust and measured the cylinder ever so carefully and thanks to all the saw gods I was blessed with the 52 mm magnum which i,m told is close to having a 044 but its a little heaver. well all it had wrong with it was a tear in the intake boot. So for 132.50 and 18.53 in shipping plus $10.00 new intake i,m the proud owner of 038 magnum . okay one more thing I broke I ripped the whole saw down just for peace of mind and at 3:00 am one morning I broke a piston ring so another few bucks on new rings and gaskets and I think its a great saw but now that i,m rambling off topic I will shut the ------ up. thanks for your time god bless and happy new year Bill