G-Series 6 Speeds
While the idea of a six-speed Porsche transaxle has quite an attractive appeal, these pricey little gems are usually not a good choice for your V-8 project. Porsche developed the majority of these close ratio short-geared boxes so that the limited power band, and extremely high RPM Porsche motors, would stay within their high RPM "sweet spot" while shifting through the gears. In other words, your first gear is way too low and virtually unusable with a V-8, second through fifth; you are spending more time shifting than standing on the gas; and sixth is a very short, under 150 MPH, disappointment. This is not like the GM six speed transmissions that boast 1700 RPM at 70 MPH. Sorry. It's more like 2800 RPM at 70 MPH in sixth... Ouch.
There is one exception. There is a few Porsche 6 speeds that have a little taller gears. They are still not nearly as tall as the GM transmissions, but it is a six speed. Call for a price if you are interested.
Ordering Terms