mph to low maybe wrong gears?

88 squared was IF you are currently running an 850 with NO PV's...

If you pull the PV out, step up the jetting 6-8 sizes.

DO NOT put the jetting square with the secondary and run a primary side PV. Only time the jetting should be squared is if you are running PV's on both ends or not.

I have no clue what you are currently running, you mention an 850. Go here and look up what the carb started out with for jetting and start there. If running a spacer, step up jetting 2 sizes front and rear from where the listing says it came stock with.

[ame]http://www.holley.com/data/TechService/Technical/Carb%20Numerical%20Listing.pdf[/ame]