Fast, maybe someone with an 81 will add some specifics to my suggestion. The electric pump should be mounted close to your fuel tank and a little lower. Don't cut up your fuel line, but use flexible line to make the connection to the hard end. As far as your mechanical pump goes, you will use a block off plate on the block and a piece of flexible line to bridge the line gap created by the removed mechanical pump. Everything will remain the same. You might like to put a fuel pressure gauge in the line, but not necessary. Any fuel not used by the engine will return to the tank the same. Don't expect any performance improvement unless your engine is starving for fuel on hard acceleration. Hope this helps.
