So Im debating wether to rip out my 4.8 and replace it with a 6.0 or rip out my 4.8, build the bottom end, and throw it back in with a good H/C setup and a KB 2.8. So what would be a good boosted cam and heads to go with on this? I was thinking about the L92 heads for starters but will they fit on the 4.8 block?

 

No on the l92's..Intake valve will contact the cylinder.
If you keep the 4.8 consider some 317's with a nice 220's cam on wide split 115-117.

 

317's, what do they come on usually?

 

The 317's came on LQ4's and LQ9's(6.0s), don't pay too much for them. Seems like you can get them for 100 bucks.

 

ARP rod bolts are the most I would do to a 4.8. You could spin that 4.8 to the moon with them. Anything more is a waste IMO, just swap a 6.0 in. The Z06 cam is a good cheap boost cam.

 

A KB 2.8 is a HUGE blower for a 4.8...

You looking for 25psi of boost?

 

And I know who has one.

 

I agree, 2.8L is overkill for a 4.8 unless you are looking for insane boost numbers(25+) like the Cobra guys do. It will probablly be close to the same money to get a good 6.0 block and put good off the shelf parts in it as it would be to get one-off parts for the 4.8. Is your 2.8L a top mount or side mount? If topmount, you will have to stick with a cathedral port head unless you get a new lower tub for the rectangle port heads.

 

I know the 2.8 is big, but I figure I'll run it on the 4.8 and see how it does while building the 6.0 long block. Then if and when the 4.8 quits Ill have a 6.0 long block ready to swap in.

 

Keep the 4.8l with the kb you are gonna have enough power but,you will need extra money.Whats going to end up happening is the extra power is gonna address all the short comings in your drivetrain/fuel system.Now if you swap a 6.0l in....Well now you will end up having more power that wont make to the pavement and less money to optimize the combo.It will not cost anything if you keep it 4.8l.
Btw...You would have to spin the **** out of that blower to get 20#'s let alone 25#'s.If you compare the ford mod motors to an ls know that the ls will consume alot more air all things being equal.What i am sayin is the 4.8l kb will need to be spun way harder to achieve the same boost levels when compared to a 4.6 mod motor.I dont have the patient to get into the math but,i will say been there done it a few times.