Id go the other way especially with the truck intake. Bigger isnt better its about the combo and time and again people on here neglect to see that the guys running the best times and making the most under the curve have cams around 220, regardless of cubes you can make huge tq numbers with the truck intake and a small cam and still have it pull till 6k rpms. The key is too go with the smaller lobes(less duration), high lift and drop the IVC and EVO we've seen it time and again and no one wants to acknowledge it.
Ive got a graph somewhere of a 402 monster with a 220 cam that looks like its got a maggie on it.
Dont buy into the bigger is better its a crappy philosophy.

Look at the numbers guys like ragtop and patG make with relatively small cams.
I could post stuff all day about this but people still run cams that are way too big. And they wonder why they dont run good times
/rant

 

Grind # 3720R/3722R HR110.0
Gross Valve Lift .581 intake/.581 exhaust
Duration at .050 220/224
Lobe Separation 110.0

http://www.exoticperformanceplus.com...Car.php?car=39

It does have a ported fast intake but you get the idea.

Ragtops: 2002 SS vert !CAGS, 3.73s, lid, ASP pulley, FTRA, 160 T-Stat, 210/222 112 110 .595/.581, Bilsteins, BMR SFC.
344 RWHP on F-Body Central's Mustang Dyno

PatG: 223/227 .637/.639 110LSA cam


Check out cajuns and some others on here

 

220/224 is to small of a cam for him IMO. You have a damn good flowing set of heads. and the shittiest manfiold. To make optimum power on motor with the 402 and the truck manifold your going to need a reverse split cam.

If you want to choose a cam for a diff manifold and just live iwth the truck manifold for now.

Ls6 manifold? I would start to look at like a 228/234 or 236. Assuming your going to run a bigger shot then 100, like 150-200. if your only gonna run 100(yah b/s lol) stay with 2-4 degree split.

Now My personal opinion, not worth to much. Maybe someone will suport me maybe not. LSK lobe all the way, if you have dual springs. Now your duration will be smaller but this will tkae benefit form your awesome heads. LSK lobes are goin gto have more lift and aggressive lobes.
It makes more torque down low then the XER lobes at smaller durations without loosing top end power.

Dont believe me? Search for patric G's thread on tech about his LSK lobe swap.

 

This is what Im talking about with overcamming with a stock truck intake I could preach this till Im blue in the face but no one listens. This build is very similar to yours.

https://ls1tech.com/forums/showthrea...light=402+dyno
No disrespect to the owner.

 

I agree with the reverse split using the truck intake. Remember, the stock cam in the 4.8/5.3 is 191/190...

I had originally planned on doing the LS6 intake swap when doing the motor swap, but the funding kinda ran out. That is my next mod though.

 

In my post above.... I stated that if he just going to use the truck manifold and soon go to a ls6 or something better then just go ahead and get .... cam. Im not recommending those cams if he keeping the truck manifold.

 

If you plan on swapping the intake, I'd get something in the 230 range at least.

 

I'd go bigger from the start.Your static compression is pretty low for a NA setup.So I would go bigger and advance it to kick the midrange up.
Off the top of my head without my books I'd say
234/238 XER on a 112 +4. That should be an excellent DD Cam in a 408ci with tons of midrange.

 

I've driven a Silverado SS with a 408 and a much smaller cam than that even. It ran just fine and drove great. A much larger cam was added later and the results weren't as big as you'd expect. Your 228/230 cam is just fine.