I have a edelbrock 650 carb and performer rpm intake on my stock 84 trans am what should my base timing be set at? sticker under hood say 4 degrees but would u step it up a bit???

Come on guys please help!

You set it to where it runs the best under most conditions without spark-knock and without hard starting when hot.
For the average carbed small block out there with non-computer controlled distributor, the best range is commonly between 10 and 15* of initial advance, not counting any vacuum advance.

Got it set at 12 from 4 and it seems to be running ok. Will i leave it there or step it up even more? why the big differeance in timing from 4 to 12 degrees like my sticker under the hood says??

When you change components like your carburetor, intake manifold, and distributor from stock, the optimum timing setting usually needs to adjust to fit the application.
Often you are getting either a cooler mixture or velocity has decreased in the intake port, which requires an earlier spark.
Actually many completely stock applications can gain performance with some increase in spark advance.
It's normal.