Exhaust Header pipes

I have a T3 that has had 1000cc Spada barrels etc installed.
I am rebuilding it but the previous owner had “doctored/welded” the exhaust down pipes in a home built 2 into 1, which is rubbish and stops it running properly. I have been given a pair of old T3 down pipes but on trying to fit them they seem very loose.
Does anyone know if the diameter of the down tubes on a Spada and a T3 are different? (looks like it to me but thought I should check)

As far as I know, they should be the same. What is loose? The headers should be a loosish fit in the head and the collets hold them in place when you tighten down the finned collars.
Don’t forget the downpipes are handed, left and right, the left is longer at the top of the pipe as the left cylinder fits slightly further back than the right one.

There is a very skilled chap that makes Stainless systems, I cant recall his name but his is near to Nigel at NBS, , it would look nice with his craftsmanship on the machine

That would be Roy of O and S Systems