ok forget all the posts that iv put on here in the past since know one knew or didnt know how to help or just didnt want to. but anyway got a o2 mc with l67 complete swap and im having a hunting idle problem and when warm the car will stall but will start right back up. also got a miss fire code p0300 it says bank 1 would this be a o2 sencer , coil pack or a ignition mod. if anybody can help me out that would be cool. the parts that i have changed are plugs,wires,maf,tps vacs line are all good

 

This may be the obvious, did you get the car retuned for the top swap? If not, that will be important.

If I recall, code P0300 is a "random misfire". Look at things that cause multiple and random cylinders to misfire. Sometimes it boils down to a bad fuel regulator, vac leak, fuel pump, pinched fuel line.....