rear end help

I'm building my first hot rod and need some info. from you that know what you're doing. I'm building a '30 roadster and need to know what is the good width of rearend to fit a fenderless hot rod? Help

 

One that puts the wheels/tires right where you want them, relative to the body.

Without knowing what wheels/tires you are going to use, it's difficult to say how wide the rearend should be.

 

Usually the "narrower" cars, Mustang, Camaro, Nova, etc, will work out easily. If you prefer older Ford, then you'll find plenty of tips here by doing a search.

 

The only REAL way to tell what the rearend width should be is to mock up the wheels and tires that you are going to use under the car with all clearances taken into consideration and measuring the distance between the inside mounting surfaces. That becomes the overall width of your rearend (wheel mounting surface to wheel mounting surface). Asking your buddy's best friend's next door neighbors cousin who knows someone that might have built a hot rod back in 1903 won't get the job done.
Now, armed with that information you can hunt the stock offerings and see if there is something that will fit the bill. Good Luck!!! I've never found one that will do the job without sacrificing looks/clearances in one respect or another. With that being the likely outcome that leaves taking a wider rearend and narrowing it and having something that is EXACTLY the right width for your application. You might get lucky and find a candidate the has to be narrowed on only one side giving you the right width and centering the pumpkin by only shortening one side.
This leaves the LIKELY option of having the housing shortened and the axles cut and resplined on both ends. Believe me if you go down THIS road you'll be well pleased with the result.

Frank