Wondering is it safe to run it with stock ecu.Alot of people say it is hard to tune obd0 and I dont have the money to convert to obd1.Some say it will run lean.Let me know what you guys think.I was thinking about just getting my ecu chipped

You want to put PR3's into you LS but you don't have money to convert to OBD1? I think you need to rethink your priorities...

Building the engine is only half the battle... the power lies in the tune... Tuning on OBD0 is weak when compared to OBD1.

To answer your question, yes you can run it on a stock ECU, but I would at least get an SAFC.

yea since I built the motor, I wasnt going to put those pistons in was just going to do ls pistons.But I plan on converting it in a few weeks

I've read up on conversion many say it is hard

It's no harder than any other obd0 car...

most of the time when people say it's hard:
They dont have experience on it yet.
It's their first time doing it.
Wiring isn't their thing...lol

Or they're going solely on what they read on the internet or what their friends tell them...