New to the auto seen. Basically got a stock 98 ss the car will be a full bolt on car with some spray maybe and will have some 373 gears in it soon. I was told that a 3500 would be to big and would slow the car. The car is not a daily driver but have to drive it to the track and still take it out to street race on the weekends. Traction not a big issue got some 15x8 m/t drag radials 275/50/15 with skinnies on the front. would love to hit 11s but will be happy with mid to low 12s for now. I ran a best of 13.4 all stock

 

A 3500 with those gears would be a realy nice stall and would not hurt you in my opinion. Regardless do not go less than a 3000 stall. You'll be hating yourself later for not going with more. The 3500 on stock cam should set you up real nice if you plan on going with a bigger cam in the future plus nitrous. I prolly wouldn't go any larger than that on a stock cam though. That's just me. I'm sure some folks like a 4k stall on it but I think that's a little up there for a stock cam and especially if you plan on using nitrous.

Side note: Get a reputable stall with anti-ballooning plates. Vigi, Yank, Pro-Torque, etc.

 

When my 00 Formula was stock with just a lid, loudmouth, no cats, and the free mods I went with a Yank ST 3500 and ran consistant 12.2-3s with a cold day best of 12.15.

In my personal experience with LS1s I would never go smaller than 3500 for a stocker and 3800 for a full bolt on car.
My heads/cam car in sig has a PT4000 Yank and it works very well.

And listen to Airborne above for the brand recomendations. A top quality converter will outperform a generic.

 

I went with a TCI 3500 and it was a nice fit for bolt ons. But ultimately I wanted more. Yank and Circle-D are my favorites for 4L60E converters. Both are top of line quality.

3600 is a minimum IMO. But I honestly wish I had gone with a Yank SS4000 right off the bat. Now I have a Circle-D 4400 matched with my cam and it ROCKS!

Good luck.