I have a set of 906 Vortecs that have been hot tanked, checked for cracks, shaved, guides milled, rocker bosses cut, screw in studs and guide plates installed, and have a new set of Comp Cams valve springs and retainers installed.
I bought them this way so I don't know how much was cut off the guides or how much was shaved off. I'm not sure if the spring pockets were cut or not. The current springs measure 1.256" in diameter, but there is a flat surface all the way around the springs where it looks like it was milled.
After checking clearances, I found the heads would be safe for use with a .480-.490 lift cam, or up to .530-.540" with raised locks.
Valves are stock.
Any idea what these things are worth? I got them cheap last year, but now I'm thinking of going with a nicer set of aftermarket heads. They are very nice pieces and will probably end up using them.
Here's a few pictures: