Assumable Wells Fargo loan for primary residence purchase

[Curt Treece]

I am under contract to purchase a property (primary residence) in Texas.  The seller has a conventional Wells Fargo loan that is assumable (yes, I confirmed that it is in fact an assumable conventional loan).  The balance on the loan is around $200,000 with a 3.75% interest rate. The gap between that loan balance and the purchase price is roughly $485,000.  None of the lenders that I am speaking to are willing to finance the difference since the second loan is subordinate.  Are there lenders who would offer a loan in second position to cover the difference (and still make it worth while considering I can get a conventional 30 year fixed for the full purchase price minus 10% down at 5.625%).  

If there is a more creative way to get this financed so that I can take advantage of the existing loan at 3.75%, that would be ideal.