valve cover

[muncie21]

If you're capable of replacing the head yourself, you should be able to complete the job in a day, 2 max. There are tons of these motors around, so finding a used head in good condition (or a re manufactured one) should be easy and relatively cheap. Material costs are pretty minimal, so I'd recommend changing it yourself if you have the time, know-how (or desire to know) and a few bucks..less than $200 is my guess.

 

[SnowDrifter]

Don't forget to have the machine shop deck your heads. Don't care if they're new or pull offs. Get 'em done

Block would be ideal but a large piece of cast iron is a fair bit less prone to warping than a piece of aluminum