Lou1119,
You're either going to have learn an awful lot about engines, or find someone you can trust to work on the engine and advise you. I was fortunate to find a trustworthy local shop owner who advised me. I had my 351W engine rebuilt twice during the first four years after hard track use revealed some shortcoming in what started as a basically stock engine. After the second rebuild it had aftermarket heads, cam, pistons,
oil pump,
oil pan, crank, and was bored/stroked to 410 ci. That was almost ten years ago and I've had few problems with it since then. ... My point is that there should be nothing inherently problematic with having a 427W, but it can give you trouble if something wasn't done right before. The fact that someone apparently used the wrong combination of cam/distributor gears is a cause for concern. As long as it's going to need to come apart for a flush and new cam anyway, I suggest you have your trusted mechanic inspect the whole engine, make a list of everything that might need attention and develop a budget for how much it will cost. You can then compare that with whatever options (e.g., a new crate engine) you want to consider. ... BTW, given what you already know about this car, I suggest you have a knowledgeable hotrod shop look over the entire car, especially the brakes, steering and suspension.