mains and rods clearances and piston oil spray?

I haven't yet measured the actual clearances of the rods and mains. How big they should be? I'll be running SBC400. Anything special I should take into consideration? The application will be turbocharged. Rotating parts are Eagles 4340 crank and 6" 4340 H-rods.
Has anyone of you made oil sprays below pistons to cool them down? What kind of injectors did you use?

The shop that does my machine work (Peto) seems to normally set my stuff up at about 0.0025"-0.003". They drilled the webs in the block and inserted small brass jets to aim oil up at the pistons. They look pretty simple, basically just small tubes.

I've seen those tubes as well, but some, I've heard, will not spray until certain oil pressure?
How are they attached to the block in your case?
Many OE turbocharged cars have oil sprays, I guess I could get jets out of them?

They're kind of hard to see in this pic, but you'll get the idea at least. I'm not sure if they're pressed or screwed in.
http://www.***boat.com/image_center/...2707oiljet.JPG

Piston coolers adapted from diesel technology, There are three jigs to drill webs then tapp and insert jets, bbc I run is .026" orifice by 1.750" , then cut channel from oil galley to jet, oil travels under shell. works great it will extend life of rings, pins exct. sprays a cloud of oil mist should be directed at spark plug side of piston at half stroke.nascar stuff, you can get jigs, expensive, and jets, cheap , from Joe at BLP products in florida.Down side is your oil system must be capable of handling the extra volume required. good luck,gg