[Pete]

Originally Posted by Locobob

Here is a dyno of a 91 before and after porting, no headers. If you compare this to your dyno you will note that yours is down on power over the whole rpm range - not just at the top. So whatever issue you are having is effecting the whole curve, probably not a collapsing air duct as that usually just shows up at the higher rpms.

Peaks at 5600
Some details please.

Pete