I have what I think is a lifter tick coming from the passenger side of my motor. I'm going to take it apart in a couple of days to fix it. Since I'm there I'm going to do a cam, lifters, pushrods, 1.6 roller rockers, headers, possibly a vented opti. and I may have some head work done. I want to run mid to low 12's naturally aspirated, on the stock bottom end. Which cam would be good for this? Do I need to do any head machining work? Would it be worth it to do the vented opt. and what other parts are needed for that? Which emissions compliant headers are the best quality and performance? I'll also want a high flow cat. Do you always have to degree the cam? I'll also need an LT4 knock module, right?

Here are the mods I have so far:
MTI cold air intake, throttle body airfoil, Flowmaster cat-back, Hurst shifter, Hypertech Programmer, 160 t-stat

Also, here are the options on my car from the factory:
A/C delete, rear defroster, 160 speedo
no power windows, locks, or cruise.

Thanks for any and all input.