I checked with the local galvanizers on weather it would effect the chassis. he assured me that it would be ok (and it was) and showed me a 4WD chassis which had just come out of the process.
I liked the idea that i didn't have to paint the chassis and it wouldn't rust in the hidden places while i had to leave it outside until my cab was finished. it cost me about AUS$300, which i thought was worth it.
Brendon