Substitution of collateral -- is it a renegotiation, extension, renewal or revision of a pre-TEFRA participant loan?

[Guest tcallow]

I have a client with an outstanding participant loan taken out before the effective date of TEFRA in 1982. The loan is secured by a mortgage on residential real property. Such loan would be deemed distributed as of the date the loan is renegotiated, renewed, extended or revised. The participant wishes to replace the security with a mortgage on other residential real property. In all other respects, the loan would remain unchanged.

I can find no guidance considering whether substitution of collateral constitutes the renegotiation, renewal, extension or revision of the loan.

Any opinions, comments or experiences would be greatly appreciated.