I have relied on Appliance Factory Parts for parts in the past and have been satisifed with thier ability to ship quickly and acurately.
Cross-over tube, ecr40/4500
Crossover tube for: ecr4000/4500 (21 3/4") - limited stock
Buy this part and as many parts as you like and pay only $9.99 shipping, within the Contiguous United States.