Whats a good cam that would mimic the characteristics of a GM847 cam for the LT1's? I'm looking for something that is a monster for power, and has a wicked sounding lobe to it.

 

anything in the 23x duration...with a 112 or lower lobe separation

 

Whats the specs on the GM847?

 

Gm12370847 --- 234@ .539/ 242@ .558 (1.5rr)--- 112 Lsa

 

MS3 MS4 T-REX. All those should be somewhat of the LS1 cam equal to the GM847 or the CC306.

 

Awesome! Would this cam work well on a car with full exhaust, a FAST intake, and a whisper lid? Or would it require new rockers?

 

Yes it will work. I have the MS4 in my car with a lid full exhaust and stock LS1 intake(have the fast just not installed yet). I love mine so far. I have stock rockers and the cam is .650 lift. I would how ever get them rebuilt by harland sharp. With any of those cams and the bolt ons you spoke of you should be anywhere from 410-460 rwhp.

 

Nice! Will that cam destroy my gas mileage?

 

I don't think you need near as much cam as recommended. If in doubt read the 'why not' about the TRex in my sig. Cams like MS3, MS4 and TRex are best with 3.73+ gears and 3600+ stall with an A4. With an M6, you'll want at least 4.10's, more if you are running a taller tire. Hope you already have all the supporting mods too (high-flow cats, off-road Y or duals, headers, lid, etc.) to take advantage of the powerband. Don't forget a good tune - excellent if fuel economy is a concern. 25 degrees of overlap make it tough to get a TRex very street friendly. MS4 still has 18.5 degrees overlap.

My advise? Look at no more than 232 duration. Actually, a 228/232 110+4 is great for cam only cars. It is still acceptable as a driver with 10 degrees overlap. Anything bigger is going to get progressively harder to tune with street driving in mind.

In reality, LS1 heads flow much better than LT1 heads, and not as much cam is required to get the same performance.

 

LG g5x-3

 

If I were to go with that cam, it would be after a full exhaust, a FAST or similar intake, and a whisper lid. Of coarse after the cam, I would get a tune. Not really looking to get different gears though. I'll probably stay with the 3.42's. Do you really think on top of those mods I would still need gears? I remember when I had a CC306 cam in my Z, it had everything including AFR heads, but still had 3.42's and it needed gears something fearse to take advantage of the cam. I just figured the LS1's would react much different.

 

LGM does not publish the durations on the G5X3, but if the numbers thrown around here are accurate, then it's very similar. I believe it is also ground 4 degrees advanced, which should boost torque and help street drivability. If you want an off the shelf cam, that is the largest I would go.
Most say the X3 is livable with 3.42's, but better with 4.10's. Is this a daily driver, or a toy? Since you asked about fuel economy and compatability with stock 3.42's, I'm thinking smaller is better for you.

 

This will be both a toy and a DD , more of a DD though. Basically I just want to make sure the cam doesn't make the car feel like a complete turd until its past 4,000 RPM. As long as it is making some decent power down low as well, then it will work fine for me and my decision to stay with the 3.42's.