Like I mentioned in an earlier thread, I am thinking about replacing my preheater with a high-flow cat. However, I plan on swapping a 351 in the future, and at this point, I don't want to install anything on my vehicle (unless I have to) that is not interchangeable with the 351. I was just wondering if the exhaust system is the same for both the 302 and the 351 engines. I've already done my exhaust once, and I don't want to spend more money upgrading my exhaust if I'm going to have to redo it when I put in the 351. Any info is appreciated.

 

i believe the 351 is wider than the 302, making the Y pipe wider for the 351. im not too sure though...

 

The 351 has a taller deck height than a 302, therefore making the heads farther apart. This being said the exaust is differnt. If your talking about Y pipes, their differnt. headers a differnt as well but not by much. They will work, just with minoe clearencing issues.