I'm considering having my stock LS1 heads Stage II ported and installing LS6 springs and retainers, and ls6 cam. What would be the best size valves to go with? Would i need anything else to make this work? And what kind of #'s should i see with these changes? Its a 2000 SS and I'm at 325 RWHP and 334 RWHP right now with MAC headers & o/r y-pipe, flowmaster, lid, SLP mass air, and FTRA kit. Any input is appreciated. Thanks

 

if your going with stage II heads do yourself a favor and get a cam that'll take advantage of the new found flow numbers. at least a 224 112 or 114 depending on tranny. get the heads and run some 918's, manleys, or look into some duals if you want. as far as valve size 2.02 intake and 1.60 exhuast are very common. and since your doing h/c might as well top it off with an ls6 intake. oh, and unless you ablsolutely love the sound of your flowmaster dump it for a better catback. flowmaster sounds good but flows at the bottom of the barrel.

 

"flowmaster sounds good but flows at the bottom of the barrel"

You are right on that. I had to change out my muffler and had no choice but to get a crapmaster and lost power! I hope corsa sends me another muffler real soon.

 

2.02 intake and 1.60 exhaust valves are the biggest you can put on stock seats. That kind of limits your possibilities but on stock cubes, you don't need any bigger than those anyway. With a good port job and different cam, you'll see big gains but to do heads without switching sticks is kind of counterproductive in a way. The two combined will be great. A good cam and heads will get an M6 car near 400 RWHP pretty easy anymore. A bigger cam will make even more.

 

Get rid of you blowmaster and those macs. they suck sorry. I dont like the way the macs sound. your looking at some serious power loss with that stuff.

What are your goals? What do you want out of the car? Stage II heads are great, but expensive. If your cool with that by all means get them. There are other ways to make power. You can get 400 rwhp with just a cam fairly easily these days. Its all about what YOU want for your car. Tell us what you want and we shall help