M62/M60 Thermostat Mod... the easy way!

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Tho my engine came from a 96 740il, I figured e39's are more regularly modded so I'll post this here. I read a thread some time ago about modding the e39 v8 (m62) to except the e34 v8 (m60) thermostat. It was a very well done mod but quite complicated as it required removal of the water pump and the entire water pump/thermostat assembly to be dropped off at a machine shop if one is not able to perform machine work him or her self. The major downside for me with the procedure was if i remember correctly, that the water pump itself had to be machined which is not something i would want to have done again in order to replace it.

What i have done does not require water pump removal or machining. Just a little cutting and tig welding... literally. No buying of extra parts other than the m60 or 8 series v12 thermostat.

Here is the stock complete 1 piece m62 thermostat vs stock gutted piece i already begain to modify
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Stock vs modified with stock m60 thermostat in place
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Close up of the work done to allow m60 thermostat to fit without spacers. About 1/2" wide x ~ 1/2" deep slits are needed so that the thermostat can sit flush in the housing and a hole for the jiggle pin to bleed air. The face inside where the o-ring sits needs to be shaved ~1 mm so that the m60 thermostat seats below the o-ring and the o-ring can make good contact with the water pump sealing surface.
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The rim of the m60 thermostat needs to be cut off flat so that the stock o-ring seal can contact the sealing surface of the water pump.
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This proceedure only took a day without any planning. I literally took it apart looked at it and accomplished it in a half a day. Once the thermostat seats properly the thing to do is weld the holes. My welds for this project were very unhappy like and are not pretty but it works and bolts back together like the stock unit. This can be done by anyone as long as you have a drill and a welder is available.