I worked on my car today so that I could try to diagnose some my problems that I listed in some of my last threads. I made some head way first off I hooked the maf back up and tried to adjust the throttle positioning sensor in doing so I got the idle down to normall but it still hesitates bad and it also pops through the intake when trying to throttle it. I have ordered a fuel pressure gauge because I think it may be running lean. My question is in the process of tinkering around with the tpi system I noticed that the harmonic balancer was thin and solid like a 350. I always thought that the 305's have a wide balancer that was hollow.The car is labeled as a 305 car and the vin says 305. So if the car is a 305 car and a 350 has been installed maybe the computer has not been updated therefore making it run lean.

 

Look on the back of the engine block on the driver's side near the tranny bellhousing. It will either have 5.0 (5.0 litre/305) or 5.7 (5.7 litre/350) cast into it if it's an 80s-era engine like it's supposed to be. You can also take the number off the block at the front, stamped into the engine block deck, just forward of the pass. side cylinder head and look it up on Mortec.com to decode what it actually is (and possibly where it came from if it's not stock).

It's also possible the balancer has just been replaced at some point in it's life.