Foreign valve springs in a Magnum

You are quite correct - I probably would have ran into the same issue with the Harland Sharp's. I know better now - thanks to all who replied. It's great to have a resource like this forum in order to successfully complete my project (my first, by the way).

The reason I was looking at the Harland Sharp set is because they are full rollers and would pick me up a few extra horses. They are quite expensive, and I think this is why I finally went with the OEM set.

My original goal was 300+ horsepower, but this should still be acheiveable with the hotter cam, 600-650cfm 4-bbl and headers.