Mine came with a 3.1. I used an engine harness from a 98-99 z34 monte or ltz lumina. I had to make a custom axle for passenger side because the HD trans never came in them cars, custom ac line, custom 3" downpipe which was a challenge, the engine is very tight to firewall in these cars compared with regal and GP. I had to get creative with the airbox, I chopped the front snorkel piece off and used a silicone elbow attached to an oval stainless tube that fits in the hole behind headlight. there a zero clean w body cars in my area. they are still quite plentiful in junkyards though.Did the Lumina come with L67?