i'm going to take a 235 head in soon to have a valve job and surface will it need hardened exh. seats put in

Good idea on an early head, not so important on a later head. Some inliners think it's totally unnecessary.

X2, I wouldn't bother.

All depends on what the engine is used for.In the last 15 years I had seats replaced on 5 235-261 heads on various engines.On all the heads the seats were pounded in from years of use.By the time a new seat was cut the valve is recessed in quite a bit.Not that a 235 is a hi performance piece,but having the valve where it belongs never hurts.And of course then you need to stick a stack of shims under the valve spring to get the height reasonably correct.And there's always the unleaded fuel issue..or non issue.
It's your call,adds about 100 bucks to the valve job.People always commented on how nice my old trucks ran......proper valve job is one reason.

Slightly oversize head is easier and cheaper.

Yup cheaper....common SBC valves.I prefer the valve seat inserts if you're going run the engine hard. They hold the valve seat cut longer than plain cast iron.But if it's just a putt around engine ,it doesn't matter.

thanks, this is going to be for a daily driver its going in a 31 chevy pickup. i will have to get the head off this week end and see what it looks like, and see what my machinist thinks. i will probibly go with new hardend seats.