I don't remember, are these the Swirl Port Heads? If so they are a bottom end truck head, and I've seen many of them cracked, unless they are the heavy duty truck head with the 3/8 exhaust valves and hardened exhaust seats installed from the factory. Those were less likely to crack but flow even less due to the 3/8 exhaust valves.
If your just looking to build a low end daily driver they should work fine.
No car yet, but I'm working on finding a Malibu Wagon, well lets just say trying to find a G-Body wagon.