What to look for in U-pull Magnum?

if you can start it before pulling it that would be best
302 heads 308 heads and magnums get small cracks between the valve seats, it is not a problem, you can run them like that for years and years and tens of thousands of miles,
how many vans and pickup trucks are on the road with 5.2 and 5.9 magnums under the hood running just fine?