Darton sleeves

I was recently reading an article and notices that Darton now offers a sleeve kit B18 and B16 motors. It claims that the kit includes an instruction manual, a new gasket and a special inserting compound. What are you guys and girls thoughts on this. Would you trust anone but Darton sleeving your block. From my understanding the tolerances are extremely tight and I dont know what all is involved in the process. I am sort of considering it and the price will probably be reaonable. Anyone with a sleeved block and running crazy boost. My goal is 500 hp and I am doubting my stock sleeves.