Help ID this engine front cover

[ghnl]

I recently bought an '84 Spider that hasn't run for a couple of years. The PO included a spare engine (or maybe that is the original engine...). Anyway, the block currently in the car has a different front cover. Attached are two pictures. The first is the block currently in the car, the second is the spare.

I was wondering if the first block's cover is different because the car originally had A/C. Or if it is out of another model Alfa.

[shoshone3]

I think I see a tachometer drive in the first picture. My 84 Spider has an electronic tach, with a blocking plate where the tach cable would connect. May be an earlier block?

[Little Italian]

The first pic is a front cover from a engine that was equipped with Spica Fuel injection. The second pic is from a mid eighties engine. The Shroud collar is the cast-in belt guard that protected the toothed drive belt to the fuel injection pump. The second cover doesn't have tha shroud. Both engines have the mounting for the Fuel Injection pump. The first one has a cover mounted to close off the oil supply and drain holes that fed the pump lubrication system. The second engine was never drilled for the pump lubrication because those engines were fitted with Bosch Electronic Fuel Injection and the Spica system was abandoned. I can also tell the second engine is from a later car because the crank pulley is only half. There is a second part that bolts onto the engine pulley to create a second sheave. The second scheave is for the air conditioning pump.