I re-installed the engine, to provide a starting point for the headers, and after a day of cutting apart a set of T-bucket Patriot Performance units, came up with these:
1 5/8th's, the tubes end up around 32 inches in length, but the 3 1/2" collector is one the large side for the little 289, so I ordered a set of collector adaptors to make them dive down to 2 1/2" for the exhaust system. Subframe connectors, and a rollbar should be next on the horizen. Maybe the NHRA March Meet won't be a stretch after all!!! Be great to have a match-up against the Whistler car, but we won't be in the same class unfortunately!!