Its been a while since I did a blueprint job on a 350 chevy small block, but they sure as heck are not any 1/4 of a inch out of specs .020-.040 on the tall side I can believe. Just depends on the block and what it was origanlly in.
Cut off a quater of a inch and I guarante you will have some serious interference problems. Sort of hard to put the head on with the piston sticking out of the cylinder, also the manifold would never fit, let alone match the ports up. I reman the 350 engine alot, but blueprint very few due the cost, people just won't pay that for a 350 when you can go with a , 372,383,406 and even a 427 small block. All the small Blocks have about the same deck height from the 265 up to the 350, and maybe the 400 It's been a while indeed since one of those has crossed my door.

Sport you gain better oiling to the bearings by cross drilling the crank and chamering the holes larger, but if a Splash guard is not installed with the mod you will lose anything you hope to gain from it, which is not much to start with. As far as clearance go's yes that will create less friction, but also can make a short life engine from doing it. You add up the pump plus more clearance and less area on the crank and you get a leaker thru the rods, sometimes Iv'e actually seen them run way low of oil pressure due this type of thing.
The tolerances on the crank & rods has best be there or else it won't live for long.
When I have a crank index ground for a hi perf engine I always ask for it to be on the bottom of the givin tolorance in the book, I'm still in the specs and don't usually have any leaking problems internally, plus I don't wind up with a unhappy customer due to engine failure.
One thing I do to a few is plug off the oil drain holes in the valley of the block, that will stop alot of the oil from hitting the crank, HP gain is 5-7 horse, again depending on the engine.
As far as blanceing go's, if someone that dosen't know what there doing you are correct, but a person that knows the correct way to balance a engine will have all the throws and rod&pistons within a couple of grams. Been then and done that when I worked for other places, but now since I don't own a balancer I have to send them out to a trusted reliable source.
Not one person has mentioned degreeing the camshaft,*S* thats also done to a Blueprinted engine. It's a little tougher on a 2stroke ,I can never find the cam for some odd reason,*LMAOROTF*