The OP says that he is having problems with a whine/whistle stating he has tried different traditional PVCs with no luck. I suggested the M/E Wagner because it's made differently than a normal PVC. My thinking it would solve the whine/whistle because it's fully adjustable to work on any engine without having to piece something together. I've found that most of the time but not always I have to get out the wallet to fix issues with these engines..lol
Hard to tell what is really causing the whistle not knowing the specifics. Like how much vacuum the engine has at idle? Does it whistle at idle, cruise or all the time?