I need help finding the right Flex plate

I have a bit of a problem. I am replacing the torque converter on my van again after the auto parts store one failed. So I decided to spend a lot of money and buy a Summit Racing Pro LS converter with a 2,600-2,800 RPM stall and an 11.063” bolt pattern. The website said that it would indeed bolt right up to an LQ4 and 4L80E transmission. Unfortunately, I have now learned after taking the transmission out that this is not the case. The flex plate has an 11.50” bolt pattern and not an 11.063”. Which leaves me very stuck, as I just spent $700.00 for the converter and the seal. I really don’t want to send it back as this should hopefully work for a very long time after I get it figured out.

I just am a little stuck right now. As I need to find a flex plate very soon to get this van working. So my question is, is there a factory GM flex plate that will fit my LQ4 and has an 11.063” bolt pattern?