SBC secret block mods?

[Sprayaway Fox]

Alrite Im reading this book and I would like to know if anybody actually does this anymore cause it is a old book.

On the blockside of the mains you tap a 2 angled small ports on each sid of the MAIN main oiling hole on each mains. Its supposed to spray on the side of the rod and when its going around to cool the skirt of the piston for Nitrous apps. But spinning lets say 6900 would you want this?
Also Smoothing /Porting out the casting for the return by the back of the lifter valley under the intake.
Does anybody shim there oil pump actually? I usually smooth out the rear main oiling hole on assembly but just wondering if anybody actually shims the pump.
Has anybody ever did this? I got a 307 sonic checked to a 350 standard bore but would like to try it out if its worth it.
PRIMARILY anybody ever do the main mod like that?
Thanx- Mike

[Sprayaway Fox]

Dont be scared to chime in what you think of these or if you know someone who did these.:)

[juicedimpss]

boring a 307 block that far would be more costly than it is worth IMO.
cleaning the oil returns from the lifter valley is a good idea,not sure i would spend the time to polish the entire thing though.shimming the oil pump.....well,maybe if running a used pump with high mileage for a low rpm application,maybe.im not sure i would go drilling the mains for oiling mods,could make the main web weak for no reason.I do like to tap the holes near the lifter bores and use 1" standoffs to allow the bottom to breath,while reducing windage from drainback on top of the crankshaft
.

[Sprayaway Fox]

My dilemma was I had a set of standard JE's I got for cheap. He had a 307 for free so hes said I could get it kleened up and final bored for 300 bucks out the door ready to assemble. Plus its sonicd' for a extra .30 yet. Plus I need a TRUE standard 350 and Ive been searching craigslist but I cant find a deal like that after maching if its a true standard yet.

That main mod is a good idea/and a lil scary to do on a fresh block but I think im gonna hold off on that. +1 on the standoffs. Thanx for the info:thumbsup

[juicedimpss]

how much will it cost to machine the 307 to a 4.000 bore? thats going to take ALOT of passes to get there from 3.875

[Sprayaway Fox]

Hes charging 300 out the door. Its already Magged, sonic checked, hot tanked, freeze plugged, and new bearings he said hed throw in a final hone if I brought him the slugs also. He usually charger 40 bucks a hole with nothing else. IDK how many passes but I know you can only take out .30 at at time.