[JLMounce]

My understanding is that all 200r4 transmissions have the dual BOP and Chevy bolt pattern and should also have a 3/4 bell. It should by that nature bolt straight up to your engine without issues related to the starter. However, because I'm not 100% sure on that, if you are looking at transmissions, verify this for yourself first.

You didn't state what engine your Star Chief has in it, whether it's the original, or a possible hopped up swap from later v8's. The 200r4 in stock form is not known to handle the torque of Pontiac engines well. In a big, heavy car like the Star Chief, that can be more of a concern.

If this is a basically stock car that is used for nothing but cruising, I don't see an issue. If the car has been hopped up at all or sees regular wide open throttle runs, a performance rebuild of either the 200r4 or a 700r4 would be recommended. Given the weight of the car and assuming the factory engine, the 700r4 may be better suited for your application. With either the 200 or 700, you are losing 1 forward under-driven gear for an overdrive gear. The 700r4 however has a gear spread and 1st gear ratio that more closely matches the original hydra-matic in your car now. Going to the 200r4 is a pretty big torque multiplied reduction over your current transmission.

The only real difference with going to a 700r4 in this application would be the need for an adapter plate. Those are readily available and economical, so I wouldn't rule it out just on that bit of information alone.