I am running the walbro 255HP, The meth kit is the CoolingMist, single stage kit. I am running a 50/50 mix of Water/Alcho, Im confused about the next question?? Protection against high boost?? you mean something like boost spike?? I am running Crome Pro and it has a adjustable boost limit setting, Ihave it set on hte street at 22PSI and at the track 27PSI. If thats what you ment, Im not sure, The manifold is the same as the SS, we just basicly hacked one up and rewelded it all together and fixed a few flaws.. We figured that it flowed well enough but needed some work to be any good..