[V8Vairs] ECM flashing?

[TNT Automotive]

This isn't realy a corvair question but thought someone may have some knowledge on ECM reprogramming. I am installing a 5.3L small block in a 66 monza, and I am just getting to the wire harness/ computer install and need to have the ECM reprogrammed to eliminate the anti theft software. I don't know who does this and where they are (Canada if possible). Any help apreciated. Thanx     Trevor