here is a rare hard to find in this condition,thinning my collection is a 1969/70 yamaha ss396 engine with 124psi both cylinders rolls over very nice has correct new ngk spark plugs and new velosity stacks on original keihein carbs and comes with the factory electronic spark box. engine is very clean.has low build number on engine 00259.i believe this is the first year of the yamaha race engines.comes with yamaha sales brochure explaining the engine and the shop manual.