I put the rear end from a 69' F250 in my 49' 3600. Worked out great. Had to weld up different spring perches and have the drive shaft shortened a bit and the U joint yoke changed to the match the F250 yoke. The pumpkin is offset like yours is. I have 3.73 gearing now and it runs great.

1949 Chevy 3600
1975 W-25 Hurst Olds
1970 GMC 1/2 ton Fleetside
2010 Chevy Silverado