Performance help!
 

As always, you need to consider goals and uses.

If you want something completely off the shelf, find a tuner, have them recommend an off-the-shelf cam they've written tunes for, and stick it on. Improve airflow with upgraded intake and exhaust paths. Call it done.

Moved over to C5 Tech.

Look at cam motion.

I would contact local performance shops relative to your area that work on LS's. There's a wide range of cams for these cars, and like gimp has suggested, finding a tuner that has tuned a car for specific cams and applications is going to get you the drivability and hp increases you desire. As an owner of a cammed C5, I can tell you, the magic is in the tune. Especially since this car is for street use. Drivability should be balanced with desired hp gains.

Auto or Stick? Big difference when it comes to camshafts. While having the balancer off is a great time to cam swap, it may be a little out of order in what you're doing. You may want to consider some bolt ons before messing with bumpsticks. Long tube header, CAI, LS6 intake would all be huge benefit with a larger cam. But a larger cam without those mods would be very restricting to horsepower. Just my .02c

Those thumper cams sound nasty at idle and that's about the end of it. Hard to tune, lousy drivability.

Corvette Camaro tuner in Tampa E85
 

You guys know you can call Comp Cams and they will grind whatever you want.

A good calibrator can make a small cam sound big and a big cam sound.............well not so big lol

This will help a lot.
http://ls1howto.com/index.php?article=1

Just hope the good deal is for a suitable cam. Do you have the specs? Auto or stick?

I love how that's article 1.

"Hey, we're making an LS1 how-to website. What do people want to know?"

"How to make it faster."

"Yeah, sounds right. Let's do that"

I would stay away from the Comp Thumper cam It is designed strictly for thr sound of the exhaust and is not a HP cam and id very hard to tune and is a dirty cam with a 109 LSA
I had a 98 car And a 98 has larger stock injectors than a 99+ cam
My 98 had 475 crank HP with the stock 28 lb injectors
I would recc the following to ahcieve 475 crank HP
1 a cam in the mid 220's of duration @ .050 Lift under .600 LSA 114 or higher
2 replace the LS1 intake manifold with the newer LS6 intake manifold
3 have your stock T Body profesionally ported
4 install any CAI
5 intstall a set of shorty headers ( if you live in a non smog state use LT headers)
6 Install a catch can--
These mods gave me 475 crank HP and was very street friendly
If you are in a no smog state you can get away with a larger cam something in the mid 230's range and a LSA as low as a 112--Plus the use of LT headers these will net you another 20-30 HP beyond my combination of 475 crank HP
ALSO if your car is an auto trans the single best mod you can make on ANY auto car is a higher stall converter-----I used a Yank 3000 stall and it made my car a beast off the line------All these mods require a re tune with full tuning software such as HP or EFILIVE otherwise you will not get the full benefit from all your changes

If you own a 1997 or 1998, you have to get a 99-04 PCM and re-pin it to use HPtuners or EFIlive. It is THE biggest drawback to owing a pre '99 C5 corvette.

There is No reason to have to update a 97-98 LS1 to a later model ECM UNLESS you outgrow the MAF table in your ECM The MAF table on a 97-98 ends at 11250 HZ ( good for approx 500 crank HP) after that until 06 the MAF table ended at 12000 HZ ( good for about 550 crank HP)
then after 07 the MAF table ended at 12200 HZ ( good to about 575 crak HP)
Howver in 08 the MAF table then ended at a whopping 15000 HZ ( good to about 750 HP)
IF you are going to use the STOCK open/closed loop system with the MAF there really isn't much more MAF table by going to even a 07 ECM
There are also other ways to tune a 97-98 ECM where the MAF sensor readings are not used exclusively----You can run a "semi open loop" tune OR a "Speed Density tune"
I have tuned boosted 98's with street boost (6 PSI) and they still fall under the 11250 table
The only way to know if you have outgrown a MAF table is to data log the MAF table at WOT in a gear ratio closest to a 1:1 ratio and you will know for sure if you want to go to the huge expense and trouble to update to a later ECM---OR if you should use a OLSD or Speed Density tune instead
Besides outgrowing the MAF table if you use your MAF and stock OL/CL system there are no differences or advatages in tuning elsewhere in the ECM ALL LS engine ECM;s are capable tuning any conbination are far as spark timing---TQ management--Power enrichment etc---no matter what year
What is your expected crank HP ????