You may need more then just the seats done. What you are looking for is a head that ends in 848 and was cast in 57 or later. 56 was the first year for the 848 head but uses a smaller temp sender in the head. 57 and up use the same size. The head needs to be surfaced flat. Mine usually take anywhere between .005 to .010 to get the bowing that generally occurs with these heads out. A nice flat head, better chance of sealing the head gasket with no issues going forward.
Valve guides, these are old heads so I can't imagine you can turn up a head with perfect valve guides, but you never know. If you find a good used head with the typical valve guide wear, you should have the valve guides lined with bronze liners, and either stick with the stock O rings for oil control (they last about two hours before they fall apart. I am exaggerating of course but they don't last long) or have the guides cut for Teflon seals. Yes, you can still buy new cast iron guides but I just don't like pounding them in an out any longer. I broke a head a couple of years ago doing just that. Now, I leave them installed where they have been for 60 plus years, drill, line and finish.
Then comes your valve job. Skip installing hardened seats. Its an extra cost that is not really all that necessary.
Camshaft, a couple of places can do a regrind. I like Schneider cams in san diego because I have never had a failure with any of their cams. Send the used cam, as well as the lifters, even if the lifters are new. They will regrind the lifters so that they are compatible with the cam grind they did.
Cam grind, lot of debate on this. Lots like the stock 261 grind. I don't. Fine for a stock rebuild of course but you can do better. The 261 truck cam was used in the vette motor because GM already had it on the shelf. Like everything else with those early vettes, GM was trying to use what it already had on hand.
Talk to a good cam grinder. Tell him what you have and what you want to do with the motor. Like I noted earlier, I like Schneider Cams. The owner at Schneider is Jerry Cantrell. He has been at this for decades. Every time I call he himself actually gets on the phone with me, and I get treated like I am some big important customer when in fact I am just a local backyard driveway hobbyist. You will get an honest recommendation.
But before you go down that road, what Clifford cam do you have? It may be just fine. Can you post the cam card you received with the cam?
