Gwoodrc, sounds like your diffs are too light. You said your track was blue groove and hard pack but didn't say if it is medium to high bite. If it is then try 7-7-5 only use 5-5-3 on loose low bite tracks.

Also please take a look at the latest setup on our site. We recently made two huge discoveries with the NB. We went to a heaver front sway bar, reduced rear tow and moved the rear hubs forward. This made the rear end extremely planted and removed all "edgyness".

The EB and NB are very similar but the weight and balance are much different. They will tune very similarly but the setups will not be exactly the same.