This is the cam you recommended for my 406. What are the spring requirements for this cam. I looked on the Lunati site and the spring speced for it is also speced for a lot of other cams with higher lift etc. Being a rookie, I thought the spring spec had to be more precise. Am I wrong?The specified spring is also a dual spring, I didn't even realize sbc used a dual spring. Would I have to remove the inner spring for break in?

Thanks for your help

Jerry

Hey Jerry, in case Harold doesnt see this quickly... you'll want around 130 seat and 330-350 over the nose on the springs. Crane 99893s will do this( and won't bind at this lift), as will others. These are 1.46" dia springs. The UD cam card recommended break-in procedure called for 1.) weak outer springs only, 2.) straight 30w, 3.) EOS, and 4.) moly lube.

I would DEFINTELY break this cam in on light springs. It's quite intense as you'll see. The valves really wip open quick and then 'gently' close. Use a tight lash for the break-in procedure of around .022". HPH.

Jerry,

427L88's advice is correct, as usual. You can go even tighter, if you wish, all the way to .018", which softens the opening ramp a little. You should get years of life out of this cam, if it's broken in properly.

427L88,

Whips 'em open, ehh? I designed one today that opens the valve 44% faster than the 276/284.
It's a little big, though. About 317 at .020, 288 at .050, 200 at .200, .616" valve lift with 1.5s. Flat tappet, of course, for the .842" tappet, and not as close to the edge as my Super NFs, a little over .017", in fact.
It probably won't get made......

UDHarold

Hey Sir, that cam in a 440ci baby rat is all I can handle on the street!!! Quite enough indeed!

Jerry, I'm looking to swap my springs soon, as they have 16K street miles and it sees 7000 rpm. Its a bit more 'fuzzy' than one would hope. You might have to shim a light pressure spring, or reach for the most height you can with a spring that looks a bit heavy. I have not found a "perfect" spring in the 1.5"OD range. Too heavy, too light, and I don;t know what brand is on the heads now ( 115/345 measured), but I wish I did, they're perfect. ( well 130/340 would be.)

In short, you have to select a spring that's close, and install them to spec.

Thanks for the help guys