Darren, this was my latest post on the topic-
https://www.mustang.org.au/forum/index.php/topic,33697.0.htmlthen I pulled them and skinned the knuckles again installing my original manifolds. Folks on this forum told me not to bother but I decided to try them. What a heap of sh@t. I have read other posts on other forums about the challenge of trying to fit Hookers to 351C and I sadly confirmed they were correct.
It may be that the 302 fit is just as challenging. From my reading, everyone ends up dinging the headers to miss steering box, idler arm, clutch etc. Good news it apparently it makes no difference to performance.
the Headers were exactly the right length to hit on the chassis connecting to the crossmember - 2 inches shorter or longer would have been much better- it is almost as though Hooker decided to make them the most difficult fitment possible. In the end the driver side was simply too low for my liking no matter what modification I contemplated.
If it is an option then return them and get some different ones. Read quite a lot of good comments about
http://www.fordpowertrain.com/FPAindex/Mustang1.htm