Does anyone know how to make a higher gear ratio like a 7.1 or 6.4 into a lower 6.0 or 5.4. Gear ratio? And where you can get the gears or parts?

Need more information to be able to help, need to know the make and model of the reel that you want to change, and what you want to change it to. Sometimes it involves more than a simple gear change.

To assist with your question, which reel?

Need more information to be able to help, need to know the make and model of the reel that you want to change, and what you want to change it to. Sometimes it involves more than a simple gear change.

revo sx 6.4:1 and i want to make it a 5.4:1

revo sx 6.4:1 and i want to make it a 5.4:1

revo sx 6.4:1 and i want to make it a 5.4:1

Do you know which generation Revo it is? The early version used a standard 1 piece spool and the newer versions used the free floating spool. The difference in spool types makes a difference in the gears that were used, in particular the pinion on the older versions was longer because it had to reach just a little further to engage the pin on the spool.

It's not really cost effective to do gear swaps when the model alternative model exists. If you decide to go that route I think the Revos of the same Generation will accommodate the Winch gear set but I'd check to be certain. The Gear set is probably around $40 from ABU. At least one of the metal drag washers needs replacing as well. My recommendation would be to buy a Winch, Lews or even PQ equivalent.

Do you know which generation Revo it is? The early version used a standard 1 piece spool and the newer versions used the free floating spool. The difference in spool types makes a difference in the gears that were used, in particular the pinion on the older versions was longer because it had to reach just a little further to engage the pin on the spool.

Generation 3

Generation 3

So here's the thing, to get the low gear ratio 5.4:1 you will have to use the gears out of the Winch. Problem is the Gen3 Revo Winch uses a sigle piece spool and the longer pinion gear. The Gen3 SX uses a free floating spool and the shorter pinion.

You need both gears to get the gear ratio you are wanting, and the longer pinion from the Winch is not going to work in your SX.

The only other Revo model that I am familiar with using the single piece spool was the Gen1 SX.

Unless that model comes in a lower ratio, it usually doesn't work to try and swap gears.

Go and get another reel with the gear ratio you want.

I forgot about the spool shaft difference as well. One more reason to just buy a reel made to do what you want. 

Years ago, I got a good deal on several of the old Green Curado's, only problem was that they were in the 3.8 to 1 gear ratio.  I had all 4 of them changed over to a 5 to 1 gear ratio and it didn't cost that much.  I got the reels cheap enough that even considering the cost of the change over and shipping the final cost was a little less than buying a new reel.  I don't think that happens too often, though.