Hey guys,

I am getting close to installing my freshly rebuilt 1974 Turbo 350 into my 82 Trans Am and I need a little help. I am a little unsure as to which drive/driven gears I need for it. First, here's some stats:

1982 Trans Am, 2.93 rear axle (RPO GU3).
Tires: 215/65/R15

Now, I've tried using the Speedo calculator here:
http://www.tciauto.com/Products/Tech...eedo_gears.asp

The tire diameter calculates to 26.00 in. The drive gear on the th350 appears to be 7 teeth (pink). Entering all that info into the calculator says I need a driven gear of 15.89. However, the TH350 gear chart below only starts at 18 teeth??? I am quite confused. Do I need to replace both drive and driven gears and if so, which ones should I get?

Thanks in advance!
Joe

 

http://www.transmissioncenter.net/sp...____va.htm#350