Torque converter bolt patterns

[Matt Cramer]

So, I'm putting a TH350 behind an 4.8 LSx, using the TH350's torque converter. I've heard some flexplates have to be enlarged slightly, like in this picture:



Mine doesn't need to be enlarged slightly, though - it needs a LOT more! Did I get some other size torque converter, like maybe a 10.75" bolt pattern? If so, is there an off the shelf flexplate for it? This may be a bit too much Demelling for my taste.