The manifold that was originally on the car was in poor shape and had been brazed in a few spots. I scored a good used one for $10 on eBay, had it sandblasted, and gave it a good coat of 1500 degree paint. Also put new bolts on that had special lock heads and washers. While I was at it, I put in a Clifford Performance port divider. That took a lot of grinding and filing but it hasn't started rattling...yet. It's supposed to increase hp by equalizing the exhaust pressure in all of the ports by turning the siamese ports 3&4 into two separate ports.