'79 440 Motorhome short block - Should I buy it?

The heads will work fine. If you're concerned what the ultimate Comp. ratio is you're going have to do some measureing. The heads will need to be CC'd cause they may have allready been shaved and one of the piston-rod assemblies needs to be installed to find out how far the piston is below the deck when at top dead center. The formulas used to determine the effective CR can be found in the tech section. A ratio of between 9 and 10 to 1 is what most builders chase depending on cam etc. running on pump premium.

Terry