Will it hurt your lt1 engine to put the heads on the opposite sides?Im embarrased to say so, but im a very newb to engine building and did this. Honestly I shouldnt have been doing it myself, but I didnt have the money to get a professional rebuild my engine, and some one I knew who does know mechanics said hed help. Then he quit halfway through, and left me to finish what he began. Long story.So anyway, I put the heads on backwards. The head cooler line I relocated, with some trouble but it works. I took off the smog pump. Everything mates up fine. However, the engine backfires, and wont start. Like I said previously it has fuel, spark, and a new distributor, plugs, wires, filters, supposedly proper timing,and the computer is good. Could the heads be the problem? I really need some input. Thanks

 

The heads will interchange sides with no problem.

 

If you have a 95 & erlier LT1 it is possible tojam the distributor in 180 deg out, you may want to check that out. Also make sure the ignition wires are going to the right place.