Originally Posted by nateobie
What do you think about using a 5.0 transmission with the 3.35 first gear? 5th gear is 0.68, and with a 24.5 inch tires and 3.909 rear end cruising 70mph speed would be 2650rpm. Think this is too tall?
Except for the input shaft length and the .73 OD, the V6 3.8 trans is practically the same as the 86-89 5.0 trans with the same ratios, but a lot less expensive. Typically, a 5.0 trans will cost over $500, sometimes way more than that. But one for a 3.8 will often sell for less than $200. Swap the shaft and its almost identical to the V8 version.
In any case, 2650 rpm is not a bad cruising rpm for a Zetec. That's going to be just about right for most engines.