After getting my engine all back together I finally got it going again but one problem perplexed me, my new sending unit which was working before I reapainted the tank does not now. After a little thinking I figure it is a ground issue. So I scapped away the new paint (ouch) from around the mounting bolts and tried that, but nothing, probably because I used a rubber gasket between the tank and the trunk. Then for giggles I decide to run a ground off the grey/red wire on the sending unit and it appears to work. My question is this safe?
Any help would be helpfull. I do not want to be going down the road in a molotov cocktail

Thanks Pesto