Hello everybody, my question is would it be okay to dent one of the headers pipes about half an inch or less to fit the motor mount bracket around it? I am pretty upset about this issue but i’m not sure on what to do. Thank you!

 

Which header is it? Generally no, you don't want to reduce the flow capacity in one pipe and not the others. But if there's no other way it'll fit.. my only advice would be that if it's a no-name ebay header, you might be better off putting the stock manifold back and saving the headache of having to do this all again soon.

 

One of the car shows from Motortrend did an experiment on the dyno with header smashing and found that there was almost no change in power from a tube until it was crushed down to 1/2 it's diameter. If you need clearance, smash it as little as you can get away with, but don't fret over it.

 

Power - maybe not, but I'd worry more about heat at the dent and corresponding exhaust port. You know how much our engines love high EGTs.

 

Hi early on with my engine swap i tried a Ebay header and because of the pipe routing the lower stud on the rear exhaust port,
it would hit and had to be dinted to fit and clear the stud, but that wasn't the biggest problem, that was the O2 sensor position,
when mounted the o2 sensor hits the firewall and it Brakes real easily and the you get messed up reading and bad fuel economy.

if your set on using the header i would go to the exhaust shop and ask them to mod the header to give you clearance.

hope this helps.