I would be very surprised if those tubes are 1 1/4. You should double check that. 1 1/2 1 3/4 more likely. Second, J tubes are your friend. Bending will not get you there. Go on to you tube and look at a couple of header fab videos and you will see what I mean.

https://www.jegs.com/i/Hooker-Headers/520/12325/10002/-1


Mike