Definitely cannot be bored out enough
But if it comes with a center rest you can do very accurate work using a bearing in your rest. A 36 inch between centers bed should allow you to just be able able to work, and bore and thread your butts.I have found that a co-ax indicator can really speed up the task of zeroing in the chuck, the center rest supported bearing, and the tailstock. I use a similar sized South Bend for much of my shaft threading and tip/ferrule work. It also has a 1 1/2 x 8 thd spindle nose. There is no way I would consider boring it out. You could not go beyond maybe an inch, and heavy removal of spindle mass will certainly affect precision of the spindle under a load. Besides it is handy to have the Morse #3 in the spindle for using a dead center to turn your material if tapering with a router on that lathe! The short dead center wastes less bed length!
One of the biggest expenses in setting up my multiple lathes was the tooling. I have spent more on my tooling than the lathe costs. If there is indeed much carbide tooling and chucks you will regret passing on that deal. You can use that tooling on the additional lathe you may buy. I have three metal lathes and want a fourth, some cuemakers here have many more I am sure. Using only one lathe makes cuemaking a chore, the set up time can test ones patience.
