Doug, the Mustang headers I bought from Mad Dog were 4 into 1 slip fit and were not a cross over design. They are basically almost identical to Hooker race headers, same design on every tube. I had to modify two tubes slightly, but I have BT heads with a raised exhaust port including the flange itself. I had a deep Canton pan and the headers were still below that.
On the REF headers, I will have to modify a couple tubes as well although different tubes, at least for my car (4-speed with modified Z-bar linkage). The tubes fit up higher than the bottom of the pan so way more ground clearance. Several tubes do come in close to the pan however, I do not think they will work at all with a T-pan, but could possibly still be cut up to work.
One thing to think of, an oil pan is cheaper than headers... LOL. I have bought a few of each. The only time I have smashed headers is when I travel over to the coast and my engine makes more power, and wheelies like a bastard. My local track I can get it to not wheelie so high and never hit the headers. I have bump stops on both upper and lower control arms, but I will have to make them a little taller, as I thought they would work as I measured everything up, but in real life, the front tires are crushing into the wheel and the rear end comes up when the front drops so hard, and compresses into the track more than what a person "figures" out at home. I also bought a Calvert single wheelie bar and will be installing that this winter sometime.
On the Shelby Stocker, Earl had to extend the bump stops further (after they hit their oil pan a while back), so it doesn't hit anymore, it has REF headers so they do not hit either (about level or a little more clearance than the (Milodon legal) deep pan, even with wheelies just as high. I can feel the bump stops bottom out, not violent... but noticeable, but no damage and no aborted runs. It is fun as hell!
