4.0 valves springs and keepers

I need to know If I can Interchange three groove valves with single groove ones and can you mix them on the same head as long as I use the appropriate retainer and keepers and spring with the valve it goes with? I could't find any posts that cover this. Any help on this would be appreciated.

AFAIK, it's doable - provided the other dimensions are identical.

Given a choice, I'd stick to three-groove all through the head assembly - three lock grooves give greater bearing area than one, minimising the risk of "valve drop." Always a good thing to avoid...

Ok , but, there is no prob. w/putting them in the older 7120 head is there? I'm doing cracked 0331 replacemennt.