Some Food For Thought...
For the sake of making the most out of any much needed design changes in the COMPLETE Oiling System that essentially moves the Source of the Oil a very considerable distance away from the previous Pool of Oil that was closer to and well below the Gerotor Oil Pump... much concentration has to be given to the Re-Design and Brazing Up of a
Larger Alternative Oil Pick Up Tube-Screen.
In the same manner that " A Shorter Straw is an Easier Draw" for drinking Sodas... The larger the Inside Diameter the Straw has... the easier it is to vacuum up any fluid (up to a point). With the additional Length of Pipe similar in design to the one
@limequat added in to the modified design of the GM 4.2L Oil Pan for his Supra 4200... comes the need to also install a Non-Stock, Wider Mouth Pick up Tube to address allowing an easier path and greater, unrestricted volume of Motor Oil available for the suction performed by the Gerotor Oil Pump... so very far away from the Oil Sump.
This On Topic Link will address all aspects of this problem..
.with the topic of increasing the size of the Oil Pick Up Tube Screen portion to assist in allowing the Gerotor an easier time of trying to get the Oil out of the Modified Sump...and up into the Innards of the Engine. Many technical issues are covered in this article that might explain the Connecting Rod Bearing Failure at the very back portion of the Engine due to Partial Oil Cavitation leaving those Bearings naked when Bubbles formed during periods of the displaced Engine Oil not being able to travel back into the Sump fast enough to replenish the Gerotor Pump. Also.. Due to its largely lateral position of the Oil Piping... this would invite the presence of any Air being sucked in with Motor Oil to float to the surface of the Oil traveling back to the Gerotor after bubbling up to the upper inside area of that Long Tube:
http://www.enginebuildermag.com/2009/06/oil-pump-technology/
...and this is a Link to
@limequat 's original work with photos showing the modified design:
https://forums.trailvoy.com/showthread.php?t=51636&page=1
And to answer the Question of
"At What Height should the Oil Pump Pick-Up Screen be Set At for Proper Performance?".... Here is George Richmond from Melling describing the typical Oil Pick-Up Screen set up in V-8 Engines that may be worth following if a GM V-8 Oil Pick Up Screen and Tubing are chosen for this adaptation down inside the Modified Oil Pan of an LL8 Engine:
By now,,, some of us are asking the Question...
"So What Bobby... Big Deal... How much Harm can Bubbles be with so much Oil getting Pumped through the Engine Block and into and around the Bearings?" The answer is dramatically emphasized in this demonstration of whether or not
The presence of Gas Bubbles in a Liquid Medium will Reduce the Hydraulic Pressure nearby enough to say... Sink an Ocean Going Vessel. The important issue to recognize here is that Reliable Engine Oiling is singularly dependent upon this One Principle:
"All Liquids Are In-compressible..."
This matters a Great Deal because if Air Bubbles get Mixed in with In-compressible Motor Oil... it is the BUBBLES that will compress and reduce the Volume of Oil present in between the Bearings and the Outer Crankshaft Journals... and when THIS phenomena occurs... The Bearings are exposed to Metal on Metal contact and very soon afterwards will Over Heat, Expand and seize to the Outer Crankshaft Journals... spinning inside of the Aluminum Block and ruining the Motor. If you don't think these principles are Universal when it comes to the Physics involved... just watch what can happen: