Be careful with the MAC headers as they do not have a flange to tie all of the tubes together. This can make it very hard to align the bolt holes with the heads, especially after a few heat cycles. I had this problem and switched to the Ford racing headers. Hedman and others also have headers with a flange that ties all of the tubes together. Whatever headers you purchase I recommend that you get them with a ceramic coating as this will cut way down on engine compartment heat.