Thanks for your reply. I'm looking at using these with a solid cam, yes I understand cam technology has improved greatly over the last 30 years or so. I know this would lead to a faster lift rate, giving a much crisper sound as well. This would also increase the over all duration as well wouldn't it?, on top of an already fat cam that you may have, so to speak.

I'm thinking of making a set for my 440, if there is any interest in these type of lifters add a comment below, I'm curious as to how much interest there might be for them.