Building a pig roaster.. HELP!!

I am looking for plans or help on building a pig roaster out of an old oval fuel tank. I would appreciate any feedback anyone can give me. Thanks a bunch!!!!!

I think we all need more information on what you're looking to do. Are you looking to make this monster charcoal, or gas? Mobile or stationary? Fixed Grate or Rotisserie? What are your technical abilities? I'd hate to give you advice and have you weld something important (like yourself) or blow something up.
Give the board a little more info on what you've got and what you're after and I'm sure you'll get lots of help!

Old fuel oil tanks cannot be completely cleaned. I roll new steel plate. The grill is thicker and is not contaminated. If you use a old tank for a grill, eat the first cooking yourself.
Chas