My toque converter doesnt lock

Hi,
Ive been away from my project for a while and I am forgetting things. The car has a 403 with a 2004r and the stock 7.5 inch 2.49 rear. I kept the CCC Carb set up. However I am running headers and never installed my O2 sensor which I intend to do. The short story is I got hurt went out on disability from work, during that time I dropped my daily driver off to get repainted. It should have been a week but for what ever reason they've had the car 6 weeks I don't want to rush them because then the car will probably come out terrible. But I go back to work on next wed so I need to put my project car on the road to go back to work. The Cutlass has the check engine light on because the O2 sensor isn't in, so Im guessing its in limp home mode. Would that keep my torque converter from locking? I like the idea of it staying in tune and getting some mpg so Id like to keep the CCC system. Worst case Scenario I did buy a RPM activated switch from MSD I was thinking of setting it to 1800 RPM and hooking it to the lock up solenoid and wiring a relay inline so when I hit the brakes it unlocks, then use a regular carb and distributor.

I don't think the gears should be too much of an issue at this point, the trans and rear are original to the car and worked with a 307. I know my 403 is putting out more power than a 307, it wont be amazing off the line but shouldn't be too much of an issue. As far as the headers Ive seen a lot of 80s Camaros with headers and they usually put the O2 in the last tube on the passenger side, how come I couldn't get a bung welded in there or even the collector and put the O2 in there? I will check but I think I have everything connected otherwise. Thanks for letting me know what to check I wasnt sure if there was more to it.

I went out and checked and I made a huge mistake guys I am sorry its 2.56 Still not great but better than 2.5 I have a Monte SS 373 posi rear the previous owner gave me that I want to put in but water got in it and its seized. I also have never rebuilt a rear before so Im waiting to get the money to have it done.

What is involved in installing the heated O2?