stay with 3:55 or go 4:10

I posted this on another board but I'll copy and paste it here as it is relative to the topic..


I am doing a axle upgrade next week and I have had all my parts for a few weeks now, Moser axles, 31 spline trac lok, 4.10 gears but after my trip to the dyno last week I boxed up the 4.10's so I could exchange them for 4.30's

At the dyno my car and the other machs there made peak HP between 4800-6300 and I'm not talking peaked there it was almost flat all the way across. These cars have a nice long power curve and they don't drop off until very high RPM's.

The dyno has the ability to tell you what gears will keep you in the power longer and for our cars NA the 4.30's were the better gear..

Here is a link from the dyno shop web page with our cars on it. Take a look at our dyno sheets and notice the nice long curve.. http://www.performance-dyno.com/pages/7/index.htm


and with the .62 5th at 70mph the car only turns 2442 rpm vs 2329 for the 4.10

wms004 said:

you are the first person i've heard say that 4.10's are a waste

Click to expand...

You can't think in terms of a GT. This is a 4V which winds out further. I am thinking in terms of a Mach 1.

RedGTvert said:

You can't think in terms of a GT. This is a 4V which winds out further. I am thinking in terms of a Mach 1.

Click to expand...

that logic does make sense, but I still don't think 3.55's to 4.10's would be a WASTE of money at all.. If you don't like winding up way over 3k on the highway and still want a performance increase, even though not optimal in 1/4 mile for the mach1, 4.10's would still be well worth the swap. my opinion

I have a 99 cobra 4v with 4.10's. wish I had gotten 4.30's. but definatly get rid of the 3.55's.