Relay and Regulator advice

The BEST way to do this is to use the fractory 70-up regulator, but you'll need to use a alternator with 2 field terminals. You'll have to run 1 wire from the second field terminal (I'm not sure where, but its a simple hookup try tech spots for where). Don't waste your money on the blue MP part. Some companies are remaking the factory 69-down regulators with electronic guts. That would be another way to go, but stay away from the MP piece.
go to bigblockdart.com and check their tech section for rewiring for late alternator and regulator.