When you increase your initial advance for your set up the starter may sound like you described. So I would not worry about it , yet. I seem to have a happy engine when I use a big cam with the timing set at 20 degrees initial on a electronic stock style distributor. I use the plates made by FBO to dial the distributor in to not give more than 35 mechanical advance. FBO has other bushings for the MSD distributors that would help you increase the initial timing further without going over 35 total mechanical. I have found with MSD distributors they don't give you the bushings with the distributors to allow for more dialing in of the timing