Hi RSMITH,

That's a great question, but a little confusing. Are you asking if a fairway wood shaft would fit in a driver?

You said that you are interested in a 55g 43" fairway wood shaft, is that correct? I don't think I've heard of a 43" fairway wood shaft, as the stock length of 3-wood is 43" with the shaft installed. So the shaft would be about 1-2" shorter when uninstalled. So this 43" shaft (not installed) would most likely be a driver shaft and I think that should play to a standard length when installed in your driver. If the shaft is 43", it should play to about 45" - 45.5" in your driver, but I would suggest to ask where you are purchasing it from, what it would play to (in length) when installed in your driver.

Also taking a shaft from a fairway wood and used in a driver, would be a bit stiffer, since it is recommended to tip a fairway wood (for a 3-wood, at least 1" is standard). So this would change the feel, flex, launch, etc. This is why most amateurs need to get fitted for the proper shaft and how they are tipped and the club built overall.

Also, why are you thinking of changing flexes in your driver shaft?

913 Driver and 3wood Nozzle adapters should interchange..

The 913/915/917 drivers, fairways, and 913/915/816 hybrids hosels are not interchangeable. You can adjust the shaft characteristics by shortening the tip end when shortening the shaft. My suggestion before spending upwards of $200 on a shaft for a 913, consider moving to getting fit for a 917. It has a so much larger sweet spot than the 913. Along with a different direction with a shaft and fine tuning the weight, I gained consistency and almost 20 yards.