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Message: <blockquote data-quote="96blak54" data-source="post: 1433376" data-attributes="member: 14727">Been mapping these cams. Ive noticed some flaws in my previous mapping and the data was incorrect. Although not to far off, im stickler about making it right. After mapping 3cams i realized a flaw in my process. Had to go back, remap those cams.....geez. oh well...all in fun!I issue the data here soon and correct the data earlier in this post.Here is the odd with my findings!The 96-98 npi cam is the most performance cam made we with almost 40Â° of overlap and desired valve events. Looking at the differences along with a pi cam just doesnt make sense. The mustang pi cam is really half of what the npi is. So, it got me thinking.The pi head has heavy valves and almost 40lb LESS seat pressure springs, which in turns suggest valve float. The pi cam has .050" more lift on the exhaust over the npi, again offering a floating valve at higher rpm.If valve float does occur with pi heads, then the pi cam makes sense. At higher rpm where the valve springs cant keep up with pulling them heavy valves back and there is also the lasher continuously pumping, maintaining follower to cam to valve pressure.....i can see why the pi cam is good.The pi cam has .040" more intake lift and favors in the npi head.So thinking that Ford designed a controlled valve float(ive always thought this along with variable lasher lashing rate) then i believe a low pound spring in the npi head would be more beneficial that swapping out to pi cams.</blockquote>