That's not bad even with the slipping trans and pretty close to my ET/MPH at 7psi. Once you get the new tranny in and the open exhaust I bet you see some 6.9x in the 1/8th. Also, one thing I noticed (actually calculated) was that my converter slips alots under boost also. You might want to get a good matching converter since the tranny is already out. Mine is an off the shelf 9" PTC 3500.
