Hello, new here, I have a 99 trans am built A4. It has long tubes into 3" ory, mild comp cam, tuned. I was ordering my slp lid and bellow Friday and can get the Ls6 intake for $300 locally. Will I notice a gain with the current mods I have with the ls6 and retune? Heads are stock along with throttle boddy. Will most likely port my tb while I'm there.

 

You'll gain maybe 10 hp and will need a retune

 

damn $300 for 10 hp doesn't sound pleasing

 

Welcome to the world of modding lol

 

with me having rear stock gear ratio will It be beneficial to have 3.73''s installed? I'm looking to notice a gain, I still don't have a stall converter or aftermarket air intake. Just cam and exhaust and tune. Adding the air lid and bellow this week and looking to add more to feel a difference

 

Look for used FAST 90/92, you will always want to upgrade, and a LS6
Is more of a restriction then an upgrade from here on out.

 

What is your current diff ratio now?
3.08:1 or numerically lower, the 3.73:1 is a great bump!
3.42:1 or higher, not so much

 

Being that you are an A4 you have either a 2.73 or 3.23 gear unless it was swapped. Wuth that said a 3.73 gear would be a nice upgrade, especially with the cam.