[QUOTE=Dominic49]It's not as simple as it sounds. The combustion chambers on the two engines are differently shaped, so just slapping the I head on an E block will get you a compression ratio of about 7.9:1, not exactly ideal for N/A. You have to find a set of pistons out of a super ETA or have a custom set made, or you can use the I pistons and shave the top of them. Either way you do it, you're going to end up throwing a whole lot of money at it. If you really want the best swap, get an M50 out of a 93'-95' 525i which bolts right up to the stock E30 transmission, and then you have 189hp, twin cams, a timing chain instead of timing belt, and VANOS on the exhaust cam, and all for less money and less labor than the I head swap. Strictly German makes adaptive wiring harnesses specifically for the M50 swap.Originally Posted by straight6
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