Transmission gearing questions

[Slither]

OK guys and gals, so after the cruise on Saturday I was picking Butch's brain on rear-end gear ratios and transmission options. He suggested the close ratio toploader with either 3.31 or 3.54 rear gears. I had been thinking that the wide ratio box with a 3.08 gear would be a better option, and here's why.

If you run the numbers with a gearing calculator (I used the SecondStrike version), it appears that first and second gear with the wide box and 3.08 rear would perform almost exactly the same as the close box with the 3.54 rear, i.e. the overall ratio (end to end) for first/second gears is 8.56/5.94 and 8.24/6.00 for the wide/3.08 and close/3.54 respectively (interestingly, first gear in the wide/3.08 combo, 8.56, is lower than first in the close/3.54 combo, 8.24!).

Next, if you look at third and forth, third in the wide/3.08 setup is identical to a close ratio box with the 3.31 gear set, while fourth is equivalent to the rear end ratio in each of the setups, since it is a one-to-one ratio in the tranny. This gives a little lower cruise rpm for the 3.08 over the 3.31, and even more difference in rpm over the 3.54 gear set.

The engines you all are running are more than capable of pulling in any of these combinations, as I witnessed (quite impressively) over this last weekend. I plan to run either the 408 Windsor or the 427FE engine, so no problem here with torque/power. The only issue I could see is that the split between second and third or third and fourth might be a bit tall for the wide box, but it doesn't seem that large from the numbers at 1.42 and 1,36 for the wide box versus 1.36 and 1.29 for the close box.

So is there any flaw in this logic? I realize that this is more of a clinical approach rather than the seat of the pants feel needed to really make a good choice. However, you can't just go and drive a bunch of Cobras of all different combinations to help you make a choice. Besides, it's the engineer in me that wants to see the numbers.

Additionally, I found a potential replacement for my lost toploader, and I suspect it is for a small block application... price is right and right now I can't be choosey. Let me know what you think. Is this too much of a compromise?