hi again, was reading post #1 of this thread is it safe to assume to go ahead with

Another way to convert 34xx with logo and enable features :

Flash full 34xx firmware
Unpack the file to an empty SD card, turn nuvi off, insert card, turn nuvi on.
remove sd
and to return to 37xx ,its logo included:
Flash full 37xx firmware
same as above,unpack the file to an empty SD card, turn nuvi off, insert card, turn nuvi on.
remove sd

without going to the pre-boot?

Thanks.