OK

I got my first time slips.

First pass ever with P235/60R15 regular BFG's
air temp 76 degrees track temp 101 degrees low humidity sunny
60' - 1.964
1/8 - 8.228@85.935
1/4 - 12.808@106.219

I was having some shifter problems so I'm not sure of the exact shift points

The rest of the runs for the night were a bit slower(low 13's) since the sun went down and I couldn't hook up at all, but all were just over 106MPH. Smokie burnouts out of the water box all the way to the 1/8 mile marker are lots of fun though.

now here is the million dollar question...
How much will I slow down if I change rear gears? It was turning about 5700 through the traps and pulling good so it seems as though the 4.11's are the right gear for the track, but I really want to drive my toy more than around town. I am on a budget so a gear vendors is probably out of the question and a 700R4 just seems questionable with a BBC making grunt down low.

Is there any way of guestimating the change in ET and MPH if I were to change to a 3.XX gear and run 26 X 9 Hoosier slicks and then 28" street tires?