The flexplate is 164 teeth, but has a 200 / 3.3 liter specific 2.75" centre bolt pattern, and neutral balance. The thing is it looks just like a 164 tooth 300/4.9 Big Six flexplate, but they have a 3" centre bolt pattern.
The Big Bell flexplates are plentiful, and available second hand on just about any automatic 1981 to 1984 I6 Fox car. 81-82 Cougars, some 81-82 Thunderbirds, Fairmonts, Fox Capri, 81-83 Fox Mustang. I've repeatedly asked for a new source, but no-one knows.
The roll out of big bell blocks was strange, as there were still high mount starter Fox body Ford 3.3's in various Fox body cars right up to 1981. You often find either the French based C3 Bordeux 3-speed or the US C4 bheind high mount starter 3.3's, or the C5 on some 1980 and 1981 variants, so you gotta be specific when you raid the lost parts.
The only auto trans for the Big Bell was the venerable C5, bascially a truck C4 with better internals and a lock-up clutch, plus a few quirks that have to be sorted out. One guy here runs one in his Comete, and its great.
The Big bell is a six bolt block. A six bolt AOD is a straight bolt up, but you just have to pilot drill the whole AOD box, as the bellhousing doesn't come off. Find special cap screws to hold the top two bolts down to the I6 block. The AOD case is super thick, and you just follow the Big Bell transmission swap in the Tech Pages.
The stall speed is 1650 rpm for the stock AOD as measured with a 215 lb-ft 5.0 V8. Whack it on a 3.3 with 165 lb-ft , and the stall speed would be even lower than that, not good for performance, way too tight. The 5.0 HO for 1983, and the SC 3800, ran a 2350 rpm stall converter, and its a good idea to use that. In stock form, AOD's are a real pudding with known weakness in the input shaft behind V8's. Little concern behind an I6. However, there are a range of better input shafts, 5.0HO /SC 3800 servo pistons, and for 165 pounds, its potentially the strongest for the box money anywhere on earth, and its efficient lock-up sequence makes up for the weight of the internals.
Lastly, the throttle valve must follow the 1984 4.9 1-bbl truck system, or at least work like it. It's the most simple set-up around, but if its not hooked up, it will self destruct the transmission in short order.
