tremec T-56 vs T600

[mattpatt]

I'll PM you Brent.

Excaliber: Here's my thinking. I had a 1970 Chevy Nova (396, ~425hp, 3400 pounds, 3.55 rear). It had a close ratio 4 speed 2.20 first that got just over 60 mph out of first (7200-7600 rpm but smaller tire diameters). It had absolutely no problem getting going (easily peel the "slippery" wheels thru first and could smoothly pull from a stop in 4th. The SPF cobra I'm considering, at ~2500 lbs with a ~550hp SBF 427 and 3.45 rear will get 60 mph in a 2.29 first (275/40R18 tires with 3.25% "squish"). Calculations suggest that the coefficient friction of the old Nova tires was ~0.9 while modern tires (calculated fro Corvette stopping distance from 70 mph) is ~ 1.15. Adding in wheel base factors and center of gravity heights to get weight transfer and correcting for effective weight increases from rotational inertial moments (~600 pounds in first) indicates that even with a 2.29 first the cobra will still overcome the tire grip capabilities in first gear (i.e. there's still wasted power). With the 2.29 I would expect, from what I've heard about cobras, that a little less ability to over-power the tires in first may actually be safer (less likelihood of spin-outs) and more controllable. Bottom line - in first it looks like way better than the Nova and still tire limited. Finally, with the very close ratios, the 6the gear doesn't go so high that it's unusable for cruising at 60 - 70 when you consider I'm planning on fuel injection to keep the torque and smoothness good at ~1800 rpm or so. So help me here. I don't have the cobra experience you (and the others here) have. What am I missing? I'm about to make a very expensive decision and need all the info I can get.

thanks, VERY much for any help with this.

Matt