Aftermarket Exhaust Manifolds Euro 360 - Worthwhile?

[scogins]

Hi folks

I understand that aftermarket headers are an extremely worthwhile upgrade on US spec 360 cars (due to the internal cats on the US OE manifold), but are there much gains to be made for Euro spec cars (that aren’t choked with cats)?

I’d imagine there’s a useful weight saving to be had by going aftermarket, but it looks like the OE Euro header has reasonably equal length primaries and a decent merger.

I’ve not dug deep into one - can anyone who has offer any opinions?

Thanks

Scott