I just bought an 83 GM and it wont start. The guy I bought it from threw a bunch of new parts at it. Voltage regulator, ECM, distributor, plugs and wires, but what I think it is, is the CPS. I've only been able to find 1 diagram online and it appears to be in a slightly different location. What I think is the CPS is very hard to get to. it appears to be in a cast housing with a metal bracket around it.... right next to the harmonic balancer. one of the bolts that appears to hold the cast metal to the block is one of the front oil pan bolts that appears to go all the way through the oil pan and out the top of this housing. I'm so confused and don't want to break something or take something off I don't need to. this car is a 1 owner, 42,000 original mile time capsule. I'd like to keep it as nice and original as possible.