What's the largest cam you ls2 guy have ran with 821 heads milled .030
 

I'm about to have my heads milled and was wondering how big of a cam I can get away with milling .030 with stock ls2 head gaskets and non flycut stock pistons with 821 heads.I currently have a btr square port
stage 2 cam. 225/238 durstion.

I'm running that cam also...not sure how much my heads was milled. Just mainly cleaned them up..went from 70cc to 68cc. They was just within my installers recommended PTV clearance.

Im running a BTR Stage 4 LS3 cam with the heads milled .025

235/250 duration

I would have liked that cam..but my engine guy said 'not enough ptv clearance. Don't know what the difference is? Read your other thread...numbers looked prettty good. I made 441/412 thru a locked torque convertor and 3.70 gears. I have the X-air intake also....big difference

I'm not sure what the difference is either. I have a good bit of clearance with mine although it did seem like it was gonna be a little tight at first.
I'd say your numbers sound right for a geared A4 car. I'm running 3.91's myself.

I am now thoroughly aware of how gains are exponential. I would not at all be surprised if the addition of my XAir added 20whp as my tuner speculated. This cam is DEF a top breather and my old setup was tremendously restrictive compared to what I have now. I am still waiting to get it back on a dyno but there was a very noticeable increase in feel. And I don't even have a very sensitive butt dyno. I'd liken the difference to when I added my longtubes.

Sorry, for the minor threadjack. OP, I'd say go big and just have your builder (or yourself) check PTV to make sure you're okay. I absolutely LOVE my cam. I wouldn't love it so much if I had to daily drive it though. 13qtr probably has a more friendly DD setup.

with the x-air...datalogging...it holds about 96-98 kpa at wot. So not much restriction. I also have a custom made 95mm maf sensor with the LS3 card style sensor. When I put a ported stock ls3 intake manifold on...it picked up 19whp at peak...more down low, and somewhere around 15 on torque.

My heads not milled at all but I'm running a 229/244 cam. 821 heads on top of a sbe LS2.