I bought a 94 with supposedly a 383, heads/cam/headers/stall/gear and it is tuned to run well.
I have no data on the build except what I can decipher from seeing. The builder of the car is MIA.

LT4 heads, lumpy cam, GM 1.6 rockers, double springs/titanim retainers, Hooker long tubes, nice SFI balancer, SFI flexplate, Yank stall and trans, 4.10 gear. That's about all I can verify. Looks like all new and top dollar - as I was told.
Can I tell if it is a stroked motor?
Any way to read the PCM, and know the paramiters? So I might get an idea what it was tuned for regarding mods?
Then perhaps as I change things and want more - I can better advise the next guy tuning. I want to swap the stock LT1 intake and tb.....
Any help appreciated.

 

If the PCM tune is locked you wont even be able to read it.
The only chance is if the tuner left some notes on the notepad embedded comments on the space provided for that matter.
Most mail order tuners dont do this.
Besides injector size and hardware verification tests that have been disabled there is not much to be learned from reading the PCM.
You can compare the tune to a stock tune and tell if the timing or Maf calibration or shift tables have been edited, or if the car is set up to run open loop all the time, and conclude something from this info, but regarding displacement there is nothing for sure.
Most tuners do not alter the cil displacement info on the tune.
All conclusions would be an "educated guess" and would be based on the experience of the person guessing.
If you have acces to tuning software, I would say its worth giving it a shot.
RG

 

You could look at the cylinder volume constant to see if it was set to something that resembles a 383. However, this isn't going to be 100% accurate because there are other ways to change fueling without changing this value.

 

ooohhh...I tried my hand at LS1 edit and coudn't get it - sold everything.
The 94 car runs great as it is - I guess I'm interested in updating the stock intake and tb - or really just the tb to a 52mm for now.
Think the car will just "learn" that swap with it's already tuned PCM?

Also my fear is losing the tune, failure - and wanting to set it back as it is...
After I figure my injector sizes, dial indicate the cam lift, ask Yank what stall it is or just tell the actual flash and brake stall - I could buy another PROM, tailored to things I know now and shift points, tire size etc. I want, right?

 

If the tune isn't locked you can read it with TunerCat. You need to get a cable. I got mine from Moates. I'd buy the cable anyway cause then you'll be able to read SES codes and monitor your sensors.

The cable is about $80 and imho well worth it.