cracked magnum heads

What are your opinions on Prostar? I found them in Fairmont WV. for $579.00 shipped. Searching on here, the machine shop had a good rating by one of our members. Also, they seem to be rated well on ebay.

NEW 5.9 MOPAR DODGE MAGNUM JEEP CYLINDER HEADS 360 RAM DAKOTA VAN CHEROKEE | eBay