[JSeery]

For starters I know nothing about using this combination. But, I would assume Ford used the mushroomed valve stems for a reason. The straight valve stems would concentrate the valve train load on a smaller area of the lifter. This may or may not be an issue with a stock cam and valve springs, however, Ford seemed to think it required a larger surface area on the valve stems. You would think these would be more expensive to manufacture than a straight valve stem so deemed required. Just my thoughts, again, zero experience with this combination!