Well ive searched quite a bit and i know i need to replace these two gears after switching to 3.45 gears from the stock ones i previously had. My question is, Does anybody have the part number or links to the right parts i need. I cant seem to find any for the 3.45 gears, the closest i can find is the 3.42 and the 3.73.

 

There's less than 1% difference between 3.42 and 3.45.

You can only change speedo gears in 1-tooth increments.

If you have a T-5, with approximately 20 teeth on the driven gear, that means the "granularity" of your adjustment is about 5%. Totally impossible to make a sub 1% change.

If you have a 700, the driven gear has about 40-some teeth; so the granularity decreases to 2 - 2.5%. Still not possible to make as fine of an adjustment as the 0.8% or so that you are looking for.

Your tires wear by a good ½", from new to old; assuming identical pressures at all times. Likewise, the pressure grows from 32 or whatever, to about 40 or more, at highway speeds; which causes the diameter to grow by about the same ½". That difference in diameter is about 2%, which affects the speedo reading by that amount. Fromo new tires at highway speed pressure, to old tires cold, is ONE WHOLE SPEEDO GEAR TOOTH in a T-5. From one brand of tires to another, could be even more than that.

In other words, the gears for 3.42, are about as close as you're going to get; and even if you got the "perfect" gears for 3.45 (which incidentally were the same ones, from the factory, as for 3.42 cars) , those other factors about the tires, will guarantee that they won't be "perfect" except in a few very limited circumstances.

"Measure with micrometer, mark with chalk, cut with axe"

 

here is a calc. so you can find what gears you need.

http://www.700r4.com/speedoCalc/speedocalc.shtml

 

http://700r4.com/speedoCalc/speedocalc.shtml

 

beat ya to it lol

 

HAHA, Great minds think alike.