[Excaliber]

4.11 in a Cobra without slicks would be useless, your only going up in smoke.

Consider the first gear ratio in relation to what ever rear gear you want to go with.

Close ratio top loader has much higher 1st gear than a Wide ratio top loader does.

Close ratio would be a good choice for a road course, keeping the rpm in the best working range through out the gears.

Wide ratio with it's lower (higher numerically)1st gear ratio would give you a better "hole shot" and thus is generally preffered for drag racing.

No matter what COMBINATION of gear ratios you wind up with: Consider your crusie rpm at cruise speed and build your motor (pick your cam) to work well for that. Cam profile for high rpm max horse power may not work well at a low cruise rpm, for instance.

One thing for sure, replicas are pretty light, traction becomes a HUGE issue. I wouldn't go "to low" (like a 3.90-4.11). Many have found BETTER ET's by launching in SECOND gear as a result of going to low.

The original race Cobras often used a 3.73 rear gear WITH a close ratio. Bear in mind they also used slicks, without them that gear ratio combination is really asking for trouble on "street tires"! MUCH more likely the car will want to spin out or swap ends when you least expect it.

Hanging out the rear to "drift" through the corners was the method used to race Cobras back in the day. Think about it!