The sniper holds that target AFR pretty well on the 2F. Doesn't really rev fast enough for it not to be able to adjust.
Sounds more like an ignition/timing issue vs. fuel.
Take a look at the MAP signal as well in the RPM area where the bog is happening. I have the data logger "always on"...
Are you using the factory US 60 distributor? Is it recurved? Where is your target AFR set for WOT operation?
Just did a Sniper conversion on my 84, and still in the tuning phase.
Peter