The 12-600-4 is another flat tappet cam. In your situation I'd go visit the local rebuilder, tell him you want a solid 350 Gen 1 SBC with a roller cam, on a budget and see what he can do. If you go to Summit Racing and plug in the criteria of SBC, Gen 1, roller cam, sorted by price low to high the first one that comes close is $3100 - http://www.summitracing.com/parts/hp...make/chevrolet but you'll never get it done for $3500 total, needing alternator, pulleys, brackets & belts, etc, etc....