2006 Chevrolet Express 3500: Torque Converter Replacement

I have a 2006 Chevrolet Express 3500 LT, short-wheelbase, 6.0l LQ4 V8. With the 4L80E transmission. Recently, I had the torque converter stop locking. The only torque converter from the local auto-parts stores is a $150 one from a brand I’ve never heard of. I’d rather stay away from it if possible. An OEM torque converter is $600-$700 depending on the retailer.

So, I want to go aftermarket. Specifically one from a reputable retailer, such as Jegs or Summit Racing. I want one with a higher stall than stock (I think stock is 1800 RPM).

This is the one I am looking at https://www.summitracing.com/parts/ape-49482

However, it says that there are two different impeller hub lengths. One is 2", the other is 2.5". But I cannot find the info anywhere; this is my last resort before I take the transmission out to find it. I hope someone could provide insight into this matter.

Thanks,
Conrad