Yep the manifolds are the same from my understanding. I would recommend that if you are doing this level of work get the 3 piece manifold from either ATS, or BD or the like. With the increased power level you will start a more hectic heat cycling and the stock OEM manifolds like to lift the head off the front corner of the block causing you to have to pulll the head to replace the gasket and resurface the head (I had to do mine because of it). The three pc manifold also brings along better flow so the twins will be happier. Look for a used one like I did - I got mine for under 100 clams used with a brand new replacement center section - yes I stole it I know....