I have a 67 c10 and i'm taking the 283 out of there and putting in a 350, would i have to replace the differential and drive shaft for any reason? and what would be the gear ratio? Any input will help, this is my first project car!
The diff won't have to be changed. but the driveshaft might need to be changed, depending on length and yoke ends. or use adapter u-joints if it is the correct length. as for your gear ratio of the rear end, if you pull the cover off look on the crown gear and it should be stamped on the side..if it's too wore out to read than you count the teeth on the crown gear and the teeth on the pinion and you divide, that will tell you the ratio.
The two blocks them self are pretty much the same besides displacement. The only reason you would even have to change out the drive shaft or anything else behind the motor is if you swap to a different transmission. All of your accessories will bolt right up depending on what year model the 350 is. If you go with a pre-80's block, which I would anyway, you will have no problems.