I just got done with my install of a slightly used set of ported NPI heads, Mod Max Valve springs, and XE278's. All I can say is WOWOWOWOW!!!!!!!!! This car rocks at idle and once it hits the powerband it hits like a shot of the juice. It revs much more freely and just pulls up to the limiter(will be addressing this issue next week.) I can tell it needs a tune real bad especially at part throttle and idle situations, but for now it's awesome. I also finished my nitrous install and am waiting to have it tuned in next week as well. I was saving for a 5.4(still going to) but I got such a ridiculous steal on the heads and cams I couldn't resist!! $985.00 for the parts and then gaskets, head change kit, etc. Not too bad eh??