[biketopia]

Stock vortec heads, LS1/6 factory beehive springs and keepers, Comp 787-16 retainers, fel pro SS72861 valve seals,and a LT4 hot cam with 1.6 rockers and you'll be right at or over your 400hp, and still run on pump gas. No extra machining, no spring bind, all easily and cheaply sourced parts. I ran this combo in my Camaro and had zero issues with it until I ignored a coolant leak and over heated the engine. Plenty of other threads all over the web of people running a LT4 hot cam and vortec's. The hot cam won't have a ton of chop to it, will still produce a good vac signal for brakes and accessories, and has a fuel pump lobe.