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I am in the process of swapping in a 2.0 16v for my 1.8 16v and wanted to make sure I wasn't missing anything. This is what I plan on doing. Since I like doing most of my own work, I will be smoothing the ports in the head, port-matching the intakes and exhaust, puting in heavy valve springs (any suggestions of brands, where to buy, would be appreciated), autotech 16v matched cam set, techtonics adjustable cam sprocket. I was curious about a header, but most people I've talked to said that the headers, so far, for the 16v weren't very reliable and is questionable whether or not they even perform better than the 4 into 2 manifold with a decent downpipe. Anyway, I will buy a 1.8L 16v head set, and a 2.0L 16v block set for gaskets. Replace the rings and rod bearings and at least plastigauge the main bearings. Check the thrust/end play and when I replace the engine, do the clutch. These are the questions I have:

3. Should I go for a header or stay with the stock 4 to 2 with techtonic downpipe (2 1/4" from downpipe to a 3" super turbo Race muffler) or buy a header or (and I have the equipment to do so) make my own header to the downpipe, or copy the tri-Y type?

4. What does it sound like the horsepower will be around? The stock 2.0L lower end is around 135 hp, with the porting, exhaust, 1.8L head, cams, cam sprocket, etc. I added up to be somewhere around 160+hp? Sound close?