I am finally getting 3.73 gears installed this week. My question is if I need to replace the sending unit for the spedo. This is going in a 95 Trans Am with auto trans. I know that my speed will be different then what it reads, I'm not to concerned about that. I just want to make sure it's not going to start shifting funny. The first garage said I needed to but the one that's doing it said it's not needed. The garage that's doing it is more known for performance upgrades.

95 Trans Am Convertable -
Moroso cold air intake
Flowmaster w/ no cat
Underdrive pully

Going from what ratio, 3.42?
Probably wont notice it....

You shouldn't need anything after the install except a break-in period and a tube to correct the speedo.

Going from what ratio, 3.42?
Probably wont notice it....

No, A4 f-bodies came with 3.23's at best. So the 3.73's with the 4L60E will work out great, especially if it is street driven a lot.

Yeah it has the 3.23's and it's a daily driver. This may be a dumb question but whats a tube for the speedo?

You need to have your pcm programmed for those gears. 94+ fbodys don't use speedo gears. They use vss sensors and computer reference.

Yeah it has the 3.23's and it's a daily driver. This may be a dumb question but whats a tube for the speedo?

Ha, my bad, type-o, that's suppose to be *tune*.