Bare EQ Magnum heads vs. machining stock Magnums?

I have heard a lot about stock Magnums cracking, seems like it's mostly minor though is it really that common for the seats to just fall out?

Also are the stock valves really that bad? What's wrong with them? I don't want to have to get new ones of those too if I can. .

I don't think the valves are bad, but the valve job could be better.
The springs the EQ's come with are pretty light (as in ok for stock cams) but not much better than that.
The EQ stock 1.092 valves can't take much lift unless you get the springs, locks and retainers set like Hughes sells. (200 bucks) and allows up to around .540 or so.

On mine the guides were real nice, but I did lap check the valves since I was swapping springs anyway.
Not that you want to do it now, but the EQ's can be bushed in the guides, have the spring seats cut deeper, longer stem 2.02 valves and really put down some flow later if you want.

I read a couple of places when I was researching the EQ about the valve seats falling out.
It's not real common, but has happened.
Apparently the common Magnum crack allows the seat pocket to get larger and in some cases it falls out.