700R4 Lock-up question

[Ole Greenie]

Hey All...I have a question about lock-up on a 700R4 tranny. I have the later version (post 86) of the transmission and I need a bit of knowlegde/wisdom about lock-up. My issue stems from the converter locking in 4th gear under slower speed conditions causing my motor to lug. Now I have a 3.07 rear gear and was wondering if this lugging was attributable to the long gear set or due to some switch or pressure valve within the trans. Should the transmission be going into 4th gear in slow speeds at all? It is about 5 years old with only about 10000 miles since bought from Bowtie Transmissions. TV cable is adjusted correctly.

Is there an adjustment that would keep it in 3rd until a certain speed or will I need to swap out gears? What is the "Normal" gear set for someone with a BB and a 700R4?

Thanks for your help!