Reinhart's Bavarian Pumpernickel Question

I recently bought Reinhart's WGB and have been reading and re-reading the Bavarian Pumpernickel recipe and my girlfriend keeps asking why I'm drooling. Silly me, I'm going to attempt something that might be beyond my abilities.

If anyone has made this, or if you can answer anyway, I have a question:

I found a slightly dented Pullman Loaf pan on discount. It is a 13"x4"x4" and says it is for a 1.5lb loaf. Reinhart's recipe is for 1482 grams or roughly 3.23 lbs., yet he talks about a single 4"x8.5" loaf pan.

So...Do I need to split the recipe, or does the fact that it is a rye bread mean my pan size will work? Is that 1.5lbs for a "normal" white bread loaf?

Any other tips?

Thanks,

John