That dimension is the same A12/A14/A15.

The bolt bosses on the side of the engine differ A14/A15 and A12. Also older A12 vs newer A12.

I got a spare A15 just put back together i can give you those measurements

If you can help I need these measurements, thinking of producing supercharger kits for A-SERIES. Using amr500 supercharger and manifold adaptor.

Will need for both short and long water pumps

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I could produce these if there is enough interest, you would have to use a steel crank hub as strength is required to avoid stress fractures. Here is my drawing i did this morning, I may also consider producing these for other engines if sample crank pulleys are supplied

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I can mill a profile but want a lathe for doing the Belt races.

Can you do it? I don't see why not. There is enough room between the V-groove and the fan itself.

I want the Fan (Water Pump Pulley) to have a 6 rib serpentine race and the traditional V on the back nearest the block.

fan pulley == water pump pulley

Front half -- do you mean adding a second groove to the pulley in front of the v-groove?

Can you make a fan pulley with a 6 rib serpentine pulley on the front half of it?

gilmer pulleys might look nice, but I'd stick with the V belts, heard horror stories of people having problems snapping mounting bolts and other issues and getting snapped bolts out of blocks and heads is a pain in the butt... hehe