motor is an m34 b35, so final version of the single cam straight six, out of a 92 535I (bigger valves, better flow, but lower compression). completley rebuilt , with long stroke crank from a 73 3.3i, bored out to circa 94 mm, with custom forged alloy pistons from Top end performance, to raise compression to circa 10.2:1, along with a schrick camshaft.. custom headers, with manual advance distributor.. matching, original italian 45 mm triple weber sidedraft carbs, on a kormann, one piece manifold, with a custom made itg air filter (out of the uk)... ported, polished, balanced, etc circa 3700 cc.. manual stering box, 3.63 final drive lsd diff, getrag 265/5, 5 speed gear box. so very simple, old style package, with a hell of a lot of torque and power. Key is carbs were dyno tuned by an weber expert, driveability is very very good..