cam

~.530" lift before you have retainer to guide issues in stock trim with some simple machining and the right springs it is pretty much whatever you can get to clear the pistons.

What needs to be machined?

83notch331 said:

What needs to be machined?

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Valve guide height for sure and probably the spring seat for a double spring if you want a cam with more than .535" or so valve lift.
EDIT: And, now you'll probably get into notching the pistons also.

Even at .530 lift it will crush your valve stem seals.

jackel200269 said:

Even at .530 lift it will crush your valve stem seals.

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Not unless you are floating the valves ... or, the retainer sets-up tighter than stock.

I must have floated the valves then. Put a .530 lift cam in a stock 460 long block, ran it couple times, pulled the valve covers and the umbrella seals were shot.