I have a 69 Chevelle with manual 4 wheel drum brakes. I recently got a new master cylinder and attempted to install it. The problem I have is the pushrod seems to be too long and parts don't appear readily available. Any help at all will be greatly appreciated.

Get the right master with deep hole for pushrod. Match it up with your old one.

I just had the problem only the other way around. Fortunately Baer makes anadapter. Don't know if they can go the other way.