Tony, sorry to hear about your bad luck on the engine. Knowing that particular set of heads, I think they are good enough indeed to make more serious horsepower at the upper RPM levels, especially after the rocker stand upgrade. But for your use they are way overkill in my opinion. They should bring a pretty price to the right guy who can really use them to get more power. Then you could start over from scratch and build a conventional head 565 with Head Hunter heads and a cast single intake manifold and have great power at a lower RPM level and not need any power adder.