Changing Gears

[rgnbull1227]

Originally Posted by roadrod2000

rgnbull1227, It looks like I have a very similar set up to what you will have with the 4.10 ratio, so here goes,
My car has a 4.27 ratio rear with a world class T-5 trans, the engine is a 289 HiPo with iron heads, dual quads and a pretty wild cam, I don't know the HP or Torque but would guess HP at someware between 350 and 400 and torque on the lower end of things. I had concerns with the 4.27s during the (rebuild) of my car, but figured that the high rpm 289 would take care of that.
The gear ratio chart that you supplied looks almost identical to mine because his transmission apears to be a slightly wider ratio making the overall first gear for you accually lower than mine (I'm at 12.596 compound)
I'll sum it up for comparison reasons going off the info on the chart
Your 1st gear -lower than mine
Your 2nd gear- slightly lower than mine
Your 3rd gear- slightly higher than mine
Your 4th gear- slightly higher than mine
Your 5th gear- slightly lower than mine
Here is what I experience driving the car around town; From a stop I always use first gear but could easily start out in second, I don’t wind it out in first so the shift to second is done before I’m halfway through an intersection, of the few times that I have nailed it in first I’m at the rev limiter (7000 rpm) before I even have time to shift. Driving around town with speeds at 45-50 I am in 4th gear with the engine at 2500-2800 rpm (a nice sound at this speed but a little high for just cruising to the coffee shop) the jump to 5th drops my rpm at 50 to 1755 ( a little low for my engine to remain happy) so for me around town I would be happier with the 3rd 4th and 5th that you will end up with but not the 1st or 2nd.
On the freeway at 65 to 70 I’m at 2280-2450 which is not bad with my engine.
Bottom line is that if I change things (and I might) I would want to end up with higher ratios in 1st through 4th and keep 5th about the same but even with the low ratio that I have the car is capable of going much faster than I will probably ever drive it.
Hope this helps

Thanks Rod. What rear did you have previously to the 4.27?