I don't know about drill press, if was to try this I'd make something that bolts in mains and one for the deck so it's supported at both ends and had adjustments that allowed a long bar to be centered, then rig up some kind of feed to the bar/cutter.
Wouldn't say it's impossible to make your own bore bar, there's a ton of people on youtube building own lathes, mills, 5 axis cnc mills, 3d printers etc.. not saying you can either though, take pics/video :)
No but i guess depends on what your doing with it, the youtube reviews I watch say the ok with softer metal.
Been looking at diy lathes on youtube I want to try to build once my garage is built.
Back in the day the difference was huge now days not as much depend which ones your comparing. If your making a living off your tools maybe snap on etc.. is the way to go but for a hobbyist no. Around here a lot of people use Canadian Tires brand of tools Master Craft and just wait for there...
I'm thinking about get one of those vacuum cleaner ones I have few porting projects coming up, I know it can't compete with high dollar ones but should get me into the ballpark.
Could you flow any 340/360 heads on the 3.78"/4" to see the effect valve shrouding because I building a 273 not sure if I should go with ported close chamber 273/318 or 340/360 head. If you happen to be bored one night.