Strip the hood COMPLETELY before you have a paint shop shoot it. Let them choose and shoot the primer prior to final paint coats. The new paints being used today have terrible reactions with other chemicals.

And if you have a hood tach with a few layers of different things (primer, paint, etc) pull the tach off the hood, strip it down completely and have them paint the tach and hood seperately.

I just went through this last year and paid the price for not doing the above.