Port matched extractors?

The extractors that came on my pinto are for a TF cortina, Pacemaker and the pipes 'square in' near the flange to match the exhaust port shape.
I picked up some no-name extractors to fit escort but they just have round pipes at the flange. How much difference does the port matching make? Are they worth the extra money? Thanks

in david vizzards 'how to modify ford sohc engines' he talks about the primaries being bigger than the ports to stop revursion pulses. He even goes on to have a manifold with a matched pipe inside the larger primary to stop the reverse pulses . dont know how this holds true today. as long as your pipes dont cover the port you should be ok. its all in the lengths, design: 4 into 1 or 4-2-1. Most headers / extractors are same diameter. There are larger diameter pipes around, typically for the high performance or 2.3 pintos. I think if you scratch around on the forums there is more detailed info.

No, they're crap!  Throw them in the bin!
 
 
 
Just kidding, I have no idea.  From what I have heard though there really isn't a lot in it for the pinto's ina mild state of tune.
 
Cheers
 
Matt

They aren't dissimilar - mine are Motivator brand which I believe is the same as Lukey. 
 
Thought I had some pic's but can't find them.
 
Cheers,
 
Matt

I have the big bore pacemakers. I had them ceramic coated and have never melted a clutch cable since. Well worth the extra cash.

Carefull using ones from a Cortina, as the propoer Cortina Pinto ones had a much more angled rake to them than proper Escort ones and will hit the firewall.  Escort ones are more vertical to go down between the engine mount and firewall....  Although pretty sure Escort ones do fit a Cortina as one set I got off a Tina did fit and one did not...