No compression on the number 5 or7 cylinders

[lifted72]

So after i lost most of the compression on every cylinder on my old 351c, i decided to replace it with a engine i picked up off of craigslist for 150. I put the engine in and got the starter on it and the did a compression test on it to find out what i was working with. Every cylinder except for numbers 5 and 7 read between 150 and 160 psi, and 5 and 7 read 0 psi. So i think because the engine has been sitting out for too long the valve seats are rusted or corroded. So i pulled the cylinder head off and did a leak down test and they wouldnt even hold fluid, so now to my question. I plan on just having the valves lapped and a quick valve job on those 2 cylinders, is there any reason why i shouldnt? Should i just rip the other head off and do valve jobs on all 16 and have hardened seats put in? I really dont have the money for that so i would rather not if it is avoidable at all.

[convincor]

If your going to go thru the trouble of tearing the top end down it'd be foolish in my opinion not to do both heads complete.

[My427stang]

I agree, and while you are getting the valves to seal, be sure you put on a fresh set of valve stem seals.

[lifted72]

So i just ended up having my dad take the head to the machine shop, and he just cleaned the seats and guides and put new valve stem seals on those two cylinders. He also included a intake gasket, head gasket, and valve cover gaskets all for $30. It really wasnt a hassle tearing it down, it only took 1 hour or so. I just cant afford to fix both heads right now, and getting it running for 30 bucks sounds like a good deal to me.

[convincor]

if it'll get you on the road, that'll work for now.