Just keep your gears and add a 3000 stall. I had a 4.8 with full bolt ons with a tci 3000 and 3.42 gears and it ran a best of 8.89 with a 2.0 sixty foot and drove like stock till I floored it. It got around 18 highway mpg.

 

The stall helped out more than anything cause it was a dog below 3000 rpms.

 

the op is trying to run the same cam i have. i have a 3200 and 4.10s. it pulls strong 3500 and up but even i wish i had a little more down low. i love torque. the combo i have is in my dd and does alright on gas if i stay out of it(which rarely happens). i say def go 4.10s coming from 3.42 cause i dont think you will notice much otherwise. and def run at least a small stall but i would reccomend at least 3k. this is all just my opinion since i have a similar setup

 

I swapped out my 3600 P.I. for a TB Stall with my factory 3.73s on a tsp220 and OEM 20s 275/55s.....about 13.5 city/18-19 hwy.........decent numbers considering theres about 15 stoplights in town........