need 8 1/4 advice

first off that math does not look like fun.
i do get both wheels to spin if i sit and power brake... could that be result of the traction bars? if i go to spin the tires cornering, the side with less load will spin. either way im not too concerned with whether or not both spin right now. but if im going to put a new rear end scheme in it, then im going to do it the way i want it. thanks for all the help guys, i really didnt want to drop 900 beans on that 8 3/4.