You cannot just "change the ring gear" on a flywheel.
The flywheel size is determined by the bellhousing, and the flywheel then dictates what ring gear will be on that flywheel. To put this another way, the bell is what determines the starter mount, and the flywheel and ring gear size must then follow that situation
I'm not well versed on the older 273 bell (which used a tiny clutch) but in the 318 / 340 cars, say, 68-9 and later, generally, the passenger cars used the small bell and flywheel, and vans and pickups used the larger one. I don't know how successful anyone is by using a pickup bell in a car. I would think not, meaning in the late 60's --80's etc
I'm not at all familiar with the bell / flywheel setup on the Dakotas
