You can use your shaft and do the following to dampen vibration Take off your old grips. Go to NAPA and find a Gates fuel line that will fit down to the tip in your shaft. Cut into 2" piece and ram down to end of shaft I use a steel rod I bought at Ace hardware. Next take a 4-6 inch piece of 1/4" sonofoam(also from Ace) and tap down until it reaches fuel line. Next step is Strawsicore( Take 2 fast food straws and stick one in to other about about 2"-crimp one for easy insertion. Then take 1/8" foam winsow insulation with stick'em back.(also from Ace) and spiral wind the straws,( This a a poor man's Sensicore) and insert as far down in shaft it will go
http://www.golfsmith.com/product/30028716/true-temper-sensicore-inserts-8-pack
,--If you like to spend money you can buy the original, but I thinks Strawsicore works better, Then take 5/8" sonofoam until it reaches butt of shaft.
I use Energy grips, but they went out of business(Great grip but was priced too high) Hireko has a Karma Air cell grip that works also-
http://www.hirekogolf.com/hireko/orderportal/catalog_presentation/by_group/0/1191/0/0/0/0/0
or the Lamkin N-Dur 3 Gen or Sting Free will also work. I did this to irons I have using for 4 years and no moisture problems so shaft breaks.