(1) There are no aftermarket oil pressure gauge kits that have a rubber line except for temporary testing.The Logistics and Dangers of what you want to do here are More Complex and Hazardous than you might think. Here are all of the serious problems you could encounter:
(1) The GM Atlas 4.2L Engine using the Power of the Gerotor Oil Pump cycling over 11 Gallons of Hot Motor Oil Per Minute around and inside of the Engine Innards at around 3.500 RPM. If you employ a Typical Black Rubber Oil Pressure Hose and it either Burns through and Bursts Open onto the Hot Exhaust Manifold or gets Cut, Shreds or Separates... then the Pressurized Free End of the Open Oil Line WILL get propelled from the escaping Oil at 65 PSI ...and it WILL Whip around inside of there like a Dropped Open Fire Hose Nozzle. This crazy 'Action-Re-Action' WILL wind up Spraying Hot Engine Oil all over the possibly Incandescently Hot Exhaust Manifold. If these unfortunate events happen and should the Hot Engine Oil Ignite... You would have an Uncontrollable, Oil Fed Fire that would almost instantaneously engulf the Engine Nacelle in Flames for as long as the Oil in the Crank Case Lasted ...and for as long as the Engine remained Running.
(2) You COULD try to use something like Flexible Nickel-Steel Brake Lines With Pressure Fittings and Bend an arrangement of Pipe that ends up stopping just short of the Engine Fire Wall. However, you would also need to Create Coil in the Oil Line long enough and "springy" enough to become like "Coiled Snake" arrangement. It would have to be there to act like a Flexible, Tubular Hydraulic Shock Absorber, right in front of where the end of that Oil Line would have to be solidly mounted onto... and Pass through the Firewall into the adjacent SUV Cabin Area. This is quite necessary to accommodate, due to the fact that since the Engine is NOT a Sold State Device... Bolted Solidly to the Body of the SUV... rather it remains free to move about... Gyrating constantly... Forwards, Backwards, Left and Right... on the Two Motor Mounts. And in time, it would make for a chance that the "Oil Piping" Bends would eventually get moved around enough to Work Harden, Crack and Eventually Fail Under Pressure. If that were to happen... You'd find yourself right back at the Original Problem of having to deal with a Fully Involved, Pressurized Oil Fed Fire in your Engine Compartment.
(3) You could try Running a Copper or Nylon Oil Pressure Line ... But then you would have the same problems, as in the case of the Nylon Line....We have already had someone try to do this very same thing (AGAINST THE ADVICE TO ABANDON THAT IDEA ENTIRELY) and after the Nylon Oil Line FAILED WITHOUT WARNING and he lost all Oil Pressure at Highway Speeds. The Happy Result here was that there was NO FIRE. However... he managed by his hard-headed determined actions to "Lunch" his Recently Re-Built Engine ...as immediately afterwards, it seized up at Highway Speeds in the process. None of the Oil Pressure Gauge Kits with Oil Lines include any External Thermal Protection Tubing to protect the Oil Lines from being exposed to all of the Excessive Engine Heat where the Line(s) would have to pass... Hidden ... and underneath the Exhaust Manifold... hugging the Passenger Side of the Engine Block to be Safely out of the way before having to make a Sharp, Right Angle Turn and get routed upwards and adjacent the Engine Firewall.
(4) The Last and Most Serious Issue concerns the Question, "What will happen if the Oil Line that gets attached to the Analog Oil Pressure Gauge mounted somewhere either On or Near the Dash Panel... and it happens to come Loose?" If it were to either Burst or Leak INSIDE OF THE OCCUPIED CABIN of the SUV where OTHER Incendiary objects are capable of lighting that Hot Oil Spray on Fire... Jesus Wept.... How in the Hell would you have enough time to get your Wife and a Baby strapped inside of a Reverse Mounted Car Seat ...Out of the SUV in time to save them if this awful thing were to occur?
Please... Consider what you are doing... and realize that all of these very real tragic consequences can be avoided entirely ...by simply suffering along with the rest of us ... and continuing with using the existing Piezo-Electrical Dashboard Gauges designed into our Trailblazers and Envoys.
My money is on it being on the bus based on it's erratic behavior, just IMHO.I'll try to figure it out on my own. The hard part is going to interface it with the guage. I think it gets a dedicated 5v signal, but I will have to confirm with a multimeter. I hope it's not part of the data bus.