You can have a cam that sacrifices nothing down low, screams through 6500 rpm, has a stable idle, and is capable of perfect manners. The one I'm using does all of the aforementioned. You could get it to idle uglier, if you wanted, by turning the idle speed down low. 226/234 115+4. 620/.620 Cam Motion custom. That along with stock ported heads and a few other tricks did 500/454 at the wheels. M6 tranny and the wife drives it just fine too.

 

And the reason that your cam works so well without the typical 10+ degree split between intake and exhaust duration is because of the ported heads.
This is because when you port the stock LS3 heads they pick up much more flow on the exhaust side than the intake, so the intake to exhaust flow numbers are closer than with the stock LS3 heads. This is the reason LS3 heads typically require a bit of help on the exhaust side and most people grind their off the shelf LS3 cams with that “exhaust-centric” big spilt.
The OP mentioned that he would use thinner head gaskets. There is no way that I would pull the stock heads and put them back on there, without either having them ported and milled or replacing them with a set of ported heads.
But, if the OP is going to use the stock heads, I would just throw a BTR Stage II cam in it and forget it.
If it were me, I would call BTR (or Pat G) and request a custom cam motion grind (something with ~225-227* on the intake, ~234-238* on the exhaust and 113-114 LSA). Then I would get a set of the GM CNC ported heads (BTR sells them with their springs and retainers installed), or alternatively if I wanted more compression, I would send my heads off to a reputable shop to get them ported and milled and then install a set of BTR .660 springs with Ti retainers and put it back together with LS9 gaskets and ARP head bolts and a good set of pushrods.

 

Yep. I bought my 2013 used with 45K miles. I wasn't going to change cams without changing lifters. With the heads having to come off for the lifter swap, there was no way I was going back with the stock heads. Got them CNC ported, cleaned, milled, valve job, and the springs of my choosing installed. TX Speed did all of that for $750. I think that service is $800 now. I actually bought another set of LS3 heads to send in for porting. Didn't want my LS3 laying naked in the engine bay for a week or so waiting on the heads to get done. I sold my original heads for what I paid for the ones Tx Speed ported. Also installed a thinner set of head gaskets. With the milling, static CR was raised to 11.2:1. A bump in compression ratio picks up power everywhere through the curve. Also helps a little with fuel eco.

 

With stock or nearly stock static compression?

KW

 

Yes, int this is, I believe with a custom cam for tq and rpm carrying, you would sacrifice some peak hp (correct me if I'm wrong) But most likely *can* be done on a [relatively] tame build

 

Milled the heads a little and used a .041 compressed thickness head gasket. I figured the static CR at 11.2:1.