After a lot of tests it appears 1 & 8 are half the temp of the other 6 exhaust manfolds, it appears the removal of the manifold, runners etc is a bit of a test - I'm glad now that some one else is doing it. Any way they appear pretty crappy and with a quick flow test, 8 is a full on tap whilst 1 is six needle sharp fine streams - the other 6 seem to have cones. . They should heat them in the bath on Monday and after a good clean, we will see. It's interesting, as I expected 1/8 to have very little flow at all, so the actual flow rate, spray shape makes a big difference.