FORT KNOX-I recently replaced the intake and exhaust gaskets on my 62 truck-235 six. The main thing is to have flat surfaces on both intake and exhaust surfaces. I had mine smoothed by a local machine shop and took the two pieces apart and put a new gasket between them. Do not tighten the two pieces until you have installed back on the block . I did not use any adhesive on the gaskets and gradually tightened the bolts from the middle out. then I tightened the two manifolds. Worked very well. Also helpes to disconnect the exhaust maniford or put something under it to hold it up until you get the manifold bolted up as that stuff is heavy!! Good Luck!
