I posted this on the 3FE board, but though I'd get some help here too: 'm in a problematic place on the finalization of the 3FJ40: 1. I need an exhaust system. Right now the standard 3F-E exhaust manifold(s) is/are on the head right now. The problem is that routing (actually, having to pay to have routed) two exhaust lines in the very small confined space in the 40 (one's immediately against the steering box) would possibly be prohibitivly costly. I obviously can not have flex tube as a permanent sol'n. 2. I've thought about placing a 2F exhaust manifold there instead, that way I could utilize the existing exhaust pipe, eliminate the problems of one pipe too close. Of course having to tap in two places for the O2 sensors somewhere along the way. The question is then, how much $$/quality for option #1 vs. how much $$/quality for option #2. Then again, /will/ #2 even be possible? I've looked at many diagrams, etc, and I think it would be, don't however know the width of each 3F-E intake manifold vs. 2F exhaust manifold. Would one year of the 2F exhaust manifold fit any better against the 3F-E head than others? It appears, and can I get validation that the exhaust join at the manifold and the manifold bolt pattern were the same from 1978-1987 or was it 1981-1987? Any thoughts? Suggestions?