Timing chain cover for '65 w/ aluminum water pump

Need help on finding a '65 timing chain cover for my '65 289. In replacing the water pump (aluminum) I discovered that several bolts had been twisted off and my attempt to re-drill/tap new holes was a bust. Now need to put a new timing chain cover on and install the water pump. Several timing chain covers I've seen listed are only for cast iron pumps. I assume that there is different timing chain cover for cars w/ aluminum pumps. Please help! Thanks.