I, like many builders have fitted the dual servo kit that Mike supplied, and a tremendous asset it has proved to be. I have went a little further in terms of breaking this week . with the addition of bigger brakes and discs. I have my sportster as an E30 kit, which has 265mm brake discs. but I have and e36 m50 engine in it, with a few modified extra horses! I came across this site on the web
https://sites.google.com/site/e30brakesolutions/home
I thought this looked like a good budget way to attempt this and so the adaptor mounting brackets with bolts, and brake hoses adaptors, flew there way across the atlantic for about £50-£60. I purchased the RX7 Fc 4 pots on ebay for £70, and rebuild seal kit for £20, and grooved/drilled discs for £70 [MTEC ebay], and my local engineers took 1mm off the centre bore for £20. It took about 1 hour to do both sides. Alas I tried to upload the pics, but after got a message to say a security token was needed,,,any ideas?? I have edited this as I hope some fotos from flickr are able to be seen at
https://www.flickr.com/photos/78885582@N04/?