Edit up front: It's tough to give advice with limited info. I read through only stuff you wrote above and used only what you said about gearing to write what I did.
________________________
Reading what you wrote you only have a 65 and 70 to choose from.
I see the cheapest thing you can do to try something different is to buy a 67 and put it on with the 13 driver. Seems like anything below a 5.0 gear ratio is too much gear from what your saying. The 67 with the 13 will give you 5.154 making it possible for you to go faster then with the almost good, 14/70.
The net of it is if your almost good with the 14/70 and a pig with more gear, chances are making it possible to go a little faster when your skill increases or you fix some other on track problem, will have a better chance of happening and helping.
> Maybe someone else will say yeah, maybe I'm right about what to try.
What gear to change to most often nets out to, hey if ya want to go faster you HAVE to take gear off, meaning putting more teeth on either the back or the front.
Putting gear on generally is only needed(assuming your already close to what is needed) when you figure because of conditions or what ever, your going to be going slower out on the track.
Hide this in the back of yer head forever> Slower, more gear; faster less gear.
It's just like your car, first gear is more gear and high gear is less gearing. The only purpose of more gear is to help you get going. If you want to go faster, get rid of gear. ... the track dictates how fast is fast and you'll never know how fast is possible without >taking gear off.
You take gear off until you hit a wall(not the wall) and then you fix on track problems and push beyond the wall. ...
If it was otherwise there would not be track records to be broken, there would just be a set number for how fast you can go.
Go fast young man go fast, throw out that gear which is holding you back. ... >unless the track slows down, then ya gota put more gear on. period.