I have a 97 K3500 with 230k on the L29 7.4l. I bought a 99 L29 complete engine to build and swap in. I have ported and flowed the heads (290 cfm on intakes), had the cam reground for more lift, tighter lsa and more advance (from -6 deg to -2), And matched and ported the dreadful stock intake manifold. It's also getting Comp Cams springs and adjustable valvetrain, stainless headers, and 29 lb/hr injectors. I haven't bought the injectors yet, so maybe you can help me find ones with tuning data available.
I recently received a 12200411 ecm from ebay with warranty and pre-loaded with a 2001 L31 express van program. I got the van vin from the gmt400 forum, so there might be hundreds of ecm's out there with the exact same vin. Will that be a problem with credits and 'licensing'? I will be buying an Hp tuning system, but I have some questions for you guys first:
1. The stock manifold is a giant intake-air heater, apparently designed to flow as little of that hot air as possible. Unfortunately, I need it to stay emissions legal in the phoenix area. So initially I will run it on the new engine and stay with the conventional L31 Maf-based program. But someday I would love to play with a real intake, like the Edelbrock Pro Flo 4 (Victor Jr efi manifold with a throttle body the size of a toilet, which I just happen to have). Such a manifold would require a speed-density os. Should I buy the mvpi2 pro version for sd tuning? Or can the regular mvpi2 handle it?
2. Spark mapping is cool and all, but isn't it an unnecessary complication? Why not just stab in a vacuum advance Msd dist and 6AL box? It would certainly simplify things with the Pro flo intake and speed density. Can ignition in the 0411 be completely turned off?
3. I have an obd2 plug and 2 pairs of red/blue connectors, one pair is to build a bench tuning harness. The obd2 port has wires in pins 2, 4, 5, and 16. Can someone post the pin connections needed to build a bench harness?
Thanks a bunch in advance! Scott