New LS1 Owners - Newbie Tech - Hey there! noob question about rear gears/torque converters.

I have a mostly stock 02' Z28 automatic convertible (mildly ported t/b, maf, lid, cut up lower air box). I use the car daily to get to work, and for road trips primarily. I would like to improve streetable performance, and use it for auto-cross, just for fun. In my experience your junk runs better throughout your build if you start at the back. So heres my question, if you have no door/glove box sticker to check your "G" code, is there another reference like the VIN to figure out what gears it came with? What are recomended? would like a cam and tune...not sure about long tubes/ exhaust since I'm in California. After reading some threads here it sounds like people skip gears, and go after the t/c. Again how high is too high, and what is the stocker? Not familiar with all this...last time I had an auto it was in a pinto station wagon...does 3500-3700 sound good? I want to run in the power band, and not kill my economy (for road trips), or my rear end. I understand the crush sleeve can be a problem if you are throwing torque at it. whats involved in converting to shims...to boil it down where do I start?:eek2:

I have an 02 z28 that was an automatic and i did a full exhaust first thing... It gave me a decsent booth of speed and i was gonna do the gears next but i decided to convert it to an M6 ... I was told that if you want to do a converter do the gears first and if its a daily i wouldnt go bigger than 3.73 gears otherwise youll lose highway mileage and if youre gonna do a cam find a converter that fits your cam ... Bigger is not always better in auto cars

I was told that if you want to do a converter do the gears first

I disagree 100%. For a 4L60E auto behind an LS1, you will ALWAYS want to do a stall before gears when looking for the best bang for your buck and most overall improvement without actually adding horsepower. Any additional gains from a street-friendly gear ratio (3.73 or taller) will be marginal once you have a 3500 or higher stall. Some people don't like the "loose" feeling of high stall converters though, so adding shorter gears would help reduce this feeling if it bothers you.

For a daily driver stock LS1, 3500ish stall would be an excellent choice. Your MPG will remain the same on the highway (when in lock-up). If you plan on a cam, depending on size you may want more stall.

As for finding the stock gear ratio, you can take your VIN number to any GM dealer and have their parts department run it through the VIS system to list all your RPOs. This will show your original gear code, though there is always the chance that gears have been changed if you bought the car used.

I disagree 100%. For a 4L60E auto behind an LS1, you will ALWAYS want to do a stall before gears when looking for the best bang for your buck and most overall improvement without actually adding horsepower. Any additional gains from a street-friendly gear ratio (3.73 or taller) will be marginal once you have a 3500 or higher stall. Some people don't like the "loose" feeling of high stall converters though, so adding shorter gears would help reduce this feeling if it bothers you.


x2 RPM

Stock IMO w/ no mods you can go as "low" as 3200. However, if you plan on cam/heads, etc. I suggest a 3600+. There is a deal with one of the torque converters, that if you buy one size, you can swap it out for a "bigger" size later on. I believe it's yank, but don't quote me on that. I'll have to do some looking again.

If unsure of gears, you can always do it the old fashion way.
Put car in air, have buddy rotate rear tire one complete turn while you count the revolutions of the driveshaft. My 02 Z28 vert came with 2.73's.