Well
You can look at this in two different ways I guess
Back in my misspent youth days ..................
Collectors like you have there ... thats all we knew about
When I got back in the hobby and saw headers for my GT
I said to myself ... that looks like a ball & socket joint
Who thought up this stupid idea
as ... its bound to hinder the flow
I then realized it would allow less of a hassle as far as ......
Ease of installation
and
More room for error with sealing
and
Less maintenance
but still
My first reaction was to poo poo the design for performance
Soooo ... having said all that ............
I'd say you got it good on one hand
On the other however ...
Those old school collectors can blow a gasket in a heartbeat
I have seen things that lead me to believe the ball & socket
design does indeed restrict the flow but how much .....
Who can say
A muffler shop would have no probs with those collectors
Grady