[Will]

Ogre - thanks for the kind words. Note that I also recommended machining the guides for viton positive seals. With viton seals in place, the metal spring hats are not needed. The metal hats only add unnecessary weight and the potential for breakage when using larger aftermarket cams and larger than stock springs. I *think* the 68404 springs are the same outside diameter as stock, but I'm not positive on that and it's better to not take a chance. Awhile back there were quite a few posts from people running Crane springs that were advertised as "stock replacement" but which are in fact slightly larger OD. While they still fit inside the shields and fit with stock retainers, it was a tighter fit in the shields and spring harmonics during engine operation caused the shields to crack & break. installing positive valve seals allows you to remove the shields and thus one potential point of failure.

sprechs69 - I may have been somewhat optimistic in that price quote as I was assuming a good portion of the assembly work done by you. Sorry about that. If you're having someone else assemble it and ship it to you, then I'd think $2500 is certainly within reason.

Note that if you did the exact same buildup on a 400 with big valve heads you could run a considerably larger cam, end up with an honest 350 horses with excellent driveability, and spend about the same money.