once there is no gap between the donut gasket (on the header) and the test pipe you should be good. my spring bolts are pretty compressed as well (but with the Berk test pipe), but i know that in stock form, they were not compressed nearly as much. some people say that when you change the header or the test pipe you should get a new donut gasket, but i never did.

 

hmm is this common to start off with such a huge gap?

 

Arthur, i did not have that huge gap when i put mine (yours) in. i'll find a pic and post it ASAP.

 

i tried to brighten it up so you can see that the header flange is much closer to the test pipe flange than in the OP's picture. also, my spring bolts weren't as compressed.

 

also note that in the above picture, the test pipe was mated to the OEM header. my spring bolts were compressed all the way when i put it up to my Mugen header. so it also depends on what aftermarket header you are running!

 

Isn't it all steel.. thus making the thermal expansion rate the same?

Meaning there will be no change

 

lol i have the same thing and i have the same gap lol
no leaks so far!
YAY!!