I tore down a 350 SDL to the shortblock today. Turns out they have a 91mm stroke. Compared to the 80.2mm of the 103 that's huge. It looks like the engine is going to get put back together for big money. I was hoping to get the crank for my TE. With a 90mm bore that would give me 3.47 Liters. The only thing I don't know is the deck heights of both engines. The 603 is 235mm but I havn't got my 103.985 on a stand to measure yet.
For those interested the 300 SDL crank has an 84mm stroke which would give 3.1L with the stock bore of 88.5mm.