So I'm finally getting around to fixing/replaceing some things on my truck. II have a k&n fter and a cat back system. I'm looking into upgrading the coil packs, and new fuel injectors too. should I get a tune done after, Or will it be OK with just thoes done?
Also has anyone done the 4.6 to a 5.1 stroker kit?

 

Also if anyone knows what works be up with my ac/heating system. When the vents are on and the rpms go up it changes to the defog ones and I don't know why. But even when the switches are off and its on the cold the aircon is on?

 

On your first post, your wasting your money.
None of it will improve power to any noticeable extent.
On your second post, you have a vacuum line issue.
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Stroking to a little over 5L from 4.6 won't do anymore than swapping to a 5.4L motor and would offer more torque.
You would be going from 262 to 305 cu/in when 5.4L swap would = 330 cu/in.
Would not the bigger boltin motor be more attractive for the effort?
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Further, the stock motor does not need better coils with a 5500 rpm limit or anymore fuel from larger injectors.
There is no more power to be had from any coil change.
Larger injectors will be closed down with shorter pulse widths to compensate for the extra fuel so you don't gain anything but possible idle roughness.
They are already capable of supplying more fuel than needed in stock size.
You have to remember the OX sensors dictate fuel injection amount under normal driving.
Beyond about 3/4 throttle, fixed fuel tables determine fuel injected when the system goes open loop and would go richer than necessary with larger injectors.
The whole system is an engineered operation such that any changes have to be accounted for so just cannot change parts at will and expect great power increases.
For example a change to K&N air filtration may offer greater flow capability but the motor still will not use anymore air. Their claims just takes your money for no real gain in a street application
If you would go stroker, at least begin with a 5.4L, have the heads ported, a pair of cams and a custom tune by a speed shop, then you will have something.
Don't forget the trans and converter upgrade from 4r70 to 4r100.
Horse power cost money, how fast do you want to go?
Good luck.

 

I just thought the stroker thing would be kinda different from everything else. Would do trick flow heads and some cams with a different manifold and larger tb. It's a work truck but I want to have fun in the weekends.
Maybe just do a lightning swap.
As for the fuel injectors it has 270k miles didn't know if they should be changed out for a better flow. Not looking to go larger.