@Manu0409
No it won't work using the methods described here as you've read. They are dissimilar hardware. There are only 3 Garmin car to truckie's navigator conversions possible that i know of:

nuvi 2x5W > nuvi 465 [HWID 0827 only]
nuvi 2460 > dezl 560
nuvi 2797/8 > dezl 760/RV 760

The key is matching PCB P/N of the units. If they don't match then simple firmware flash won't work and if you force a flash the unit may brick. [Only registered and activated users can see links. ].