Right.. I had a look at the 034 k04 mani which came off Wellys S3 last week last night. The replacement arrived yesterday (thankyou Issam), however there are some worrying aspects about the cracked one and its replacement. see below.. make your own conclusions 1st thing was to attempt a repair to the crack on #4 runner, preheating the manifold before hand.. with a very odd heat pattern. Only one side of the cracked manifold would heat up as seen... the other side would not get to an even temp. Some very odd material in this section, and or wall thickness, so no surprise at all there is a large stress raiser if one side glows red easily whilst the other does'nt.. Differential expension = Crack! Once welded it looked like this. The melting point of the material was Very Low. Very few amps were requried before this material puddled and sank..a strange soft material with a low melting point.. Way less than a std factory manifold which I also weld repaired to try and compare known ok quality vs 034. K03 repaired crack below. Also preheated with the same blow torch and it would not glow at all unlike the 034 which glowed easily on its one side of the crack? Now the other runner crack was attempted to weld repair, with resultant epic fail. Again the material when pooled had all manner of slag rising out of the material, and aa very low ampage was required to melt the parent material. No matter what I tried with pre-heating with the torch, as soon as the castign started to cool, it would Tink, Tink and a crack reappeared next to the weld. Point to mention here is this Tink Tink is the exact same sound Welly reported the manifold made on cooling down after first being fitted. Castings should not make this noise, its contracting and cracking when it does. For the crack to reappear next to the heat affected zone adjacent to the weld is not uncommon, however, it would just not stop, and finally a portion away from the welded section also broke/cracked, so I called it a day. The thing is simply made from very poor material, and has serious manufacturing issues and defects. Cracked again near the welded bit.. The New Replacement (issues) As delivered, curious as to why 034 Motorsport had been badly ground off? Why would someone do this? And the issues on the new manifold.. Porosity, chemical metal filled? ? ? Pictures of area's in question which look filled to me with a material which looks like chemical metal. surely not.. The material these are cast from is nothing like as high temp as a factory manifold. Simple test of ampage on the tig welder and blow torch confirm this. The debris coming out of the 034 manifold when welding confirms the material is poor and contaminated. The casting shows significant porosity also, and on the replacement, what looks like a vein attempt to "fill" some cavity with a material? Remember these manifolds see >900'C temps in normal service. I am absolutely stunned at the abysmal quality of these 034 manifolds. Very poor material choice (cheap) has ruined what could have been a good product. Casting issues also very evident with respect to the prorosity seen. totally unacceptable to me, for anyone to be offering these for sale. There is no way simply ceramic coating the manifolds will remedy the inherant issues evident on the 2 I have seen. Shocked.. and extremely dissapointed in all concerned offering these to folks and taking their money for them!