Crossfire NV Posted September 8, 2013 Hey. I just picked up my NV3500 HighRoof. Looking to see if anybody has converted to CNG yet. I haven't crawled underneath yet to see if there's room to mount tanks. If you've converted. Let us know what kit you used and where the tanks are mounted. Also tell us if you notice any difference in engine performance. Quote Share this post Link to post Share on other sites