M60 exhaust headers vs. M62 / S62 headers

[m60power]

I've been searching across the interwebs and can't find a concrete answer, so apologies if this topic has already been discussed... I always thought the M60/M62/S62 engine exhaust headers were all the same. However, it appears the identical E34, E32, and E31 M60 exhaust header part numbers (same for b30 and b40) are different part numbers than the M62 (non-vanos) / S62 headers (which share part numbers). Interestingly, the M60B30 and M60B40 engines in the E38s share the M62 non-vanos / S62 header part numbers...

What are the differences in geometry and / or performance between the E34/E32/E31 M60 exhaust headers, and the E38 M60 / M62 non-vanos / E39 S62 headers, if any at all?

[moroza]

Held in my hands, E39 non-VANOS M62 and E34 530iT M60 headers appeared identical except for the length of their downpipes.