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I need some opinions here, I have a T-5 with a 4.03 first gear ratio, Im putting in a granada rear end with 2.79 gears, should I go with a lower gear in the rear, or will this be fine for street performance?
 

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Are you sure that you have a 4.03 first gear? I have never heard of one that low. If that is right you will have the same with 2.79 as a toploader with 2.78 first gear would have with a 4.04 rear gear.


69 Mach 1 427 Windsor
 

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The T-5 with the 4.03 first gear is from a 4 cylinder Turbo Coupe. This is not the transmission you want for a V8. Not only is it weaker, but the input shaft is a different length and diameter.

As far as gear ratios are concerned, your first gear final drive would be:

4.03 x 2.79 = 11.24

If you have a C4, first gear is 2.24, therefore to get the same final drive you would have to install a 11.24/2.24 = 5.02 ! rear end.

I would suggest selling your transmission and looking for a 90-93 (5.0L V8) transmission with 3.35 first gear if you intend to keep rear end gears in the 2.80 to 3.25 range.

Check out this page for T-5 specs: www.geocities.com/2bav8/t5data.html
 

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I put a T5 in my 67 this year and I have the 2.79 rear gears (with 3.55s going in soon).

My T5 has a .63 fifth gear and at 2000 rpm I'm running at 82 mph!! The 3.55s should give me much better acceleration, but still give me pretty good freeway mileage.

It really depends on what you will be using the car for, but my .02 is that the 2.79s will drive you bonkers: I almost never get into fifth right now and I know my acceleration could be better...
 

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If you'll post your gear ratios, tire size, and what other rear gears you are considering I'll print you a chart. I made a little program when I was deciding which 6 speed gear set to buy. To see an example check this chart out for my car

http://home.earthlink.net/~gp2mff/gr/r76_350.htm
 

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gp001,
checked out your website, what a hoot. I was nearly in tears reading the "tools & tips" page.

Nice car by the way, I love the 6 speed idea.
 
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