Maybe you could by taking the new valves and some lapping compound to lap in and seat match the new valves to the old seats, but that can be a hit and miss thing when it comes to getting a good seal. And that does nothing to address the valve guide issues that are most likely there. Better to just rebuild the heads.
If the valves are the same size, guides feel tight and the valve face and seat look to be in good shape then give them a lap and see how the sealing surface looks. Rebuilt heads are better, however $30 to buy a lapping kit > $750+ rebuild bill. If you are willing to take a gamble, I'd say try it. Just don't advertise them as rebuilt....
I'd say yes, you can, I wouldn't consider it a good plan or a long term fix, the seats that are there are worn, you can get some kind of seat lapped in but it will be very narrow and will degrade rapidly. If it's to get to a vehicle on the road so you can get to work, then do what you have to do. Other than that, plan on some machine work. You might be better keeping the worn valves and worn seats, at least they have worn together. What's a leak down test showing?
Yes indeed take your heads to the machine shop and let them grind the valves thinner and grind on the seats and sink the valves. Pay them money to make your heads not as good. Or install good valves with thick edges. and lap them with compound. install the valves and springs and fill the ports with gas. If the gas doesn't leak your golden. If the guides are really bad you will have to fix them. slightly worn guides will still be serviceable by using umbrella type valve seals.
The Jalopy Journal
