Had the same problem with my 97 TJ. 4.0. In the first 50,000 cracked 2 headers (both replaced under wrty by dealer). Cracked again, by that time I was fed up. I bought a Banks system (dealer handled the labor no charge). Banks lasted 140,000 miles. It just started to crack down by the collector. I've talked to Banks and they are going to warranty it. They're sending me their new "Revolver" model. The rep said they've run into some high mileage cracking in that area, that's why they did the redesign and reinforced that area on the Revolver. I've been very pleased with Banks customer service. The labor really isn't going to be a problem as i'm rebuilding my engine at the same time. So I either go with Banks or the newer 2 piece from Jeep.