What should the timing be for a fatory 350tpi? It came from an 89 firebird formula with a 700r4. Thanks!!!

 

They came from the factory with a 6* advance, but you can run 8* and still run 87 octane.

 

leave it stock unless you run high octane fuel

TPI has a knock sensor, you won't here the knock, but the ECM will be retarding your timing

I run 94 octane all the time(canada) and have my base timing set to 8*
I'll still see alot of knock retard on a hot day as much as 11* at WOT

with your timing at 8* and running 87 its possible your sending your car in to low octane mode,
low octane mode is a less aggressive spark table put into effect when knock is sensed over an extended period of time,

which is actually worse,

really to stay out of low octane mode you should run 91 octane with 6* base timing

the real way to adjust your timing is with a custom prom

get a datalogger and check your knock retard,

main problem with adjusting your base timing is your effecting the whole timing curve,

you should adjust timing through datalogging and custom tuning of a chip,