[DMXF]

With all the touting of newly produced FE parts, everyone seems to be forgetting the biggest shortcomings. These new engine parts are often produced by small outfits which don't have the resources or production volumes don't support the level of extensive QA that Ford had. The inspector at these shops can often be the owner or has to report to the owner and what gets let out the door will be correlated with how profits are going.

Even when parts are coming out looking pretty good, they still usually have more variability than OE Ford parts. For example, I've seen at my local engine builder how you often have to play games with the new parts like elongating pushrod holes in intakes because of interference, which is far more rare in OE parts.

From what I've seen designs of new aftermarket parts are also typically not developed to the same degree as OE items with the same diverse group of highly educated & skilled engineers and technicians from various disciplines (structural experts, metallurgists, etc). Sure, certain areas of the new parts have been beefed up, but that is often accompanied by alot of extra material where it isn't necessary. For example, I've seen numerous Blue Thunder heads at my local engine guy's shop and the general production quality looks decent (better than Dove), but they are so porky with excess aluminum it's not funny. That approach wouldn't make it far in F1 circles.

For what the original 427 engine was intended for, less than 500hp but usually good for at least 600, it's hard to beat the product. There are just a few areas (like rod bearings a bit too large in diameter and too narrow, which is primarily responsible for the windowed blocks) that if addressed make it a nice engine - and most of that stuff was being corrected by race teams back in the 60's, like using Chrysler rod bearings. The biggest problem with the old parts is finding anything decent left, as Keith has mentioned. All the problems you can experience with a new aftermarket part can sometimes negate the advantages.