[Sixteen Tons]

So, I just swapped out my 48 yr old dying starter for a remanufactured one on my 69 250 inline. Fortunately this takes all of about 20 minutes. First crank and there is a terrible squeal and clicking noise. Any suggestions on the problem and/or solution??? I'll be doing this in the rain today, so hopefully it's a quick fix!
Thanks all !!!