Dave you're taking a big gamble if you buy a set of used aluminum heads. I bought a set of used Edmunds heads for my 53. I thought they would look cool since they don't make that brand anymore. Well cool wasn't the word after I got them on. One had a hairline crack on top I couldn't see on top and leaked coolant. After two failed attempts to fix it with JB weld, I took it off for the second time and finally found a pro welder to seal it for me so far. The welder said that the older aluminum is very difficult to tig weld. So my advice is save yourself some aggravation and save til you can afford new heads. At least get them pressure checked if you buy used.