what harmonic balancer should I get for my 340?

The fluid dampner is thicker that the stock one and you will have to buy a shorter crank pulley to use it .And also have to space out the other drives a little bit to match.I did mine and used a march crank pulley for a 440 .It turned out well ,but was a hassle.My advice is get a stock thickness balancer and not have to do alot of fab work