zippy

I'll throw my opinion in there. Since you're running LS7 style heads you have a huge intake port and therefore will not need as much intake duration as you would if you were running cathedral port heads. The exhaust duration I agree with Rick is going to control your rpm range. With yours being in a street/strip truck and being boosted I'd shoot for no more than a 6200-6400rpm shift point. Keeping in mind your head choice I'd go with an exhaust duration of no more than 230º and intake duration of 215º-220º. The LS7 style head having so much flow on the intake side once again, no need for as much duration. As for the lift, I'm assuming you're running an oil cooler and aren't planning for 100k+ miles out of the setup. With that being the case I'd go for lift in the .625" to .650" to take advantage of the flow from the heads you picked. As for the LSA, I'd go for a 114 at 0.

DrX

iTrader: (7)

Plenty of food for thought here.

Would you add any advance if going with a static CR below 9:1?

zippy

I wouldn't set something up with that low of compression, but either way I wouldn't advance it. You have alot of cubes to make up for the lack of torque. You also aren't concerned at all about how well it drives around or you'd have compression higher than 9:1.

DanaliHD

iTrader: (5)

I'll say from my experience so far(just a month or so), driving a 6000+ lb truck with only 8.5:1cr isn't very fun. feels more like a 82 malibu with blown head gasket and no muffler, lol.

get it up to 50mph or so and it's nice

leftcoast32

iTrader: (4)

The TrailBlazer SS has 10:1 cr with 370 cubic inch and the SSR has 9:1 cr with 427 cubic inch. The SSR still has more low end grunt from the extra cubic inch, I was all happy with building the 427 at 10:1 until I talked with Kenny Duttweiler and he sugested we drop it. The SSR will be getting the L92 heads from Richard installed soon with alot more boost then he has had to date.

supersub

iTrader: (25)

Mine is @ 10.1 as she sits,can easily add or remove some if nesc.

DrX

iTrader: (7)

I believe we are looking at 8.8:1 with these pistons/heads. Which is about the same as the stock 454 in my old K2500 HD Sub. At least I will see be over 1000lbs lighter than it was, and any lack of throttle responsiveness will be limited to the first few mm of pedal travel.

gao8302

iTrader: (13)

I went with 9.3-1 CR. I think it worked out perfect. Good for boost and as it sits now it is N/A and drives like a dream. Good power. I threw around going 8.5-1 CR and steered away from it. Just my .02cents.