The add on ebay looks very good and it convinced me to give them a shot. Here is what I experienced:
1. Upon bolting up one of the heads (right out of the box), 2 of the rocker arm studs pulled the treads right out of the head. I called up the company in TN and the rep says send them back and they will repair or replace. They put in an insert and sent them back. (2 wk turnaround)
2. The heads require "customizing" of the guide plates. They have to be bent to line them up with the valves. No big deal really. Takes some time. They also require non-stock length pushrods. Not that of a big deal.
3. Finally get them on the motor, and am very impressed with performance. Gained 10 mph!!!
4. Exhaust valve broke and cratered the motor at approx 70 hrs on the heads.
5. Upon removing the non-broken head, I found that the water passage was severely corroded, and would have become another problem very shortly. It was about to leak into the combustion chamber!!
These heads were 11 months old!!!!
Note: Recently installed a 100 shot of nitrous. Hit the button 5 times for no more than 5 seconds at a time. Nitrous sys had timing retard, and progressive controller.
Anothe note: Bought heads assembled and the salesman at skip white assured me that I did not have to replace the ex valves with inconel.