My friend has an LS1 swapped 81 camaro, Recently switched to fuel injection using a pcm from a 99 Silverado 5.3, I helped him get it all hooked up and flash his pcm with minor changes to the stock 5.3 base tune it had, such as turning off vats, turning on power enrichment, adjusting the engine settings displacement etc. to match the 5.7 ls1, made sure firing order was the same, all that basic stuff otherwise no changes were made to spark tables or fueling besides PE. His mods to the engine: stock ls1 bottom end, Brian Tooley stage 4 cam, 243 heads w/ fresh valves, stock 5.3 truck intake, 42 lb injectors, stock throttle body, 6.0 MAF sensor, & 1-7/8? long tube headers to 3? x pipe exhaust. Now surprisingly enough the car started up running on the reflashed stock 5.3 base tune, but very rough and wouldn?t stay running. Does anyone have a similar huge cam ls1 tune that they could email to me that would be able to land us in a closer ballpark? Once we get it running good enough to drive down the street I can get a good data log file and we should be able to help it find it?s happy place after that point, but as of now it?s stuck in the garage until we get a tune that works with that big cam. If anyone can help please email me back at [email protected] or pm me here. Hopefully this beast can get back on the road this summer!