Hy kswillie, I believe 1947 was the last year for the sliding gear four speed transmission, and the older design three speed, both these transmissions had a smaller bolt pattern than the newer transmissions. In one way you're lucky, your 47 doesn't have the clutch and brake pedals mounted to the bellhousing, so you could use a 48 - 53 bellhousing, and everything should work perfectly, hope that helps.
