what gains to expect
In theory the top mount should flow better vs the elbow and TB but I doubt you'd gain as much from the TB swap as the exhaust.
We run a 2" primary to 3 1/2 exhaust in a 406 and we haven't touched the chassis yet, but we still went 9.30's with a 1.30 60ft on a baby shot.
It's gone 9.70's on the motor so far but we haven't really messed with it much lately.
How much stall are you running? We have a 6k in ours and we run a glide too.

