Help on new transmission gear ratios
 

I have a 60 F100 I will be putting a 302 into.
I am looking at a Tremec TKO500 transmission and it comes in two flavors.
Input Shaft Diameter: 1.125 in.
Input Spline Quantity: 26

or

Input Shaft Diameter: 1.063 in.
Input Spline Quantity: 10

Both have a 31 spline output shaft.
How do I know which would be appropriate for my truck?

The gear ratios are as follows.
First Gear Ratio: 3.27:1
Second Gear Ratio: 1.98:1
Third Gear Ratio: 1.34:1
Fourth Gear Ratio: 1.00:1
Fifth Gear Ratio: 0.68:1

My truck has the stock rear axle which is an 3.70 open differential(non locking).
I have 15 inch rims and do not remember the tire size at the moment but they are not real tall. I am guessing about 5" off the rim.

Will the gear ratio for the Tremec TKO500 above work well with this axle or am I going to end up changing things later? My goal is to be able to take off reasonably quick but have the truck be a daily driver that holds well at highway speeds.

Another option is the TKO600 which has the following gear ratios.
2.87
1.89
1.28
1.00
.64

My engine is 300HP so I thought the TKO600 was overkill but if the gear ratios work better....

I have not decided yet on hydraulic or mechanical clutch. I really like to be able to feel the clutch, it gives me a much better sense of what is going on but am open to opinions.

Thanks.
Trent

You can plug in your ratios here:

Novak Conversions - Gearing & Gearing Math for Jeeps

25" seems like a pretty short tire, so figure that out first.

The taller first and closer ratios would be "better" for aggressive street driving.

The lower first gear will launch you a bit easier and will be your friend if you haul anything.

Those OD ratios are plenty tall for your 3.70 axle imo.

Thanks for the response.
The link you provided was for 4x4 calculations but I was able to do the calculations on Tremec's web site and it plugged the gear ratios in for me so that made it easier.
My wheels are actually 26.1 on Tremec's calculator. I am not sure where the extra height comes from cause when I calculate it I get 24.25. The tires are 235x.60x15. I like the low stance of the truck.
If I understand correctly if I want to go with larger wheels at a later date I can switch up to 4.11 rear differential to help balance things out?

I think the lower ratio transmission will work best. I want it to be quick on the take off but not a racer. I will certainly be pulling loads with it so the extra strength pulling on the low end will be good.

I will not be able to start on the truck until next spring but I want to figure out all of the components I will be using and begin acquiring them over the winter. I need just about everything but the engine and rear axle so there will be plenty of bits and pieces for me to acquire. I think I will end up fabricating a transmission mount.

I have no idea what I can use for headers though as I do not know what the clearance is going to be once I get the drivetrain aligned.

The calculator works for 4x4 or 4x2.

Use your actual tire diameter, not off a chart or whatever.

You are correct, if you go with a larger tire, you can change your axle to 4.11 or whatever you want to compensate for the diameter, and keep overall gearing where you want it.

How much are you going to haul/tow with this truck?

The lower gears in the trans make sense for a truck.

A hydraulic clutch will solve some clearance issues, as you won't have the z-bar etc in the way. Some will swear by a mechanical clutch for feel. I've had both, and it makes no difference to me. IMO you can feel the clutch just fine with a hydraulic.

Probably best to shop headers, but wait till you have some measurements. Don't buy cheap headers.

On the driveline alignment, are you familiar with the angles required to keep things vibration free?

http://www.hurst-drivelines.com/file...roc_111606.pdf

I have a 3.07:1 first gear in my '60 F100 with the same rear end ratio and a supposed 350 hp. First goes pretty quick but it feels good. I would estimate a low 14 in the quarter mile but that's just a guess.

The fifth gear ratios are almost the same for each tranny, but with the 3.27 first gear you'll really have the get up and go- the best of both worlds. That is the tranny I'd get. The TKO600 may have you wanting to change your rear end gear for something lower.

I was in a similar boat as you when I was swapping engines in mine. I just wanted to know how fast it was going to be...the previous vehicle had a 2.73 rear and it was not at all fast. I thought I'd be looking for 4.11s (or lower) and purchased a Trac Lock unit because I was thinking that the tire (singular) would always be spinning. By the time I got it all buttoned up and started driving it, I didn't really have a problem with traction (as long as it's dry), but this isn't a daily driver for me.

I have read up on drivetrain alignment but it has been years. I will refresh my knowledge before actually beginning. I hope to get back to working on it this spring, it has been sitting way too long.

This is good to know. I will probably be happy with how it drives once the new transmission is in, just wanted to get an idea of what to expect from those gear ratios to make the best decision. Still a lot of work to do before it is back on the road but I miss driving it.