LOL I did headers & motor mounts at the same time. I think I spent more time screwing with those stupid mounts than I did installing the headers. My only advice is get someone to help you and don't tighten bolts until you get all the other ones started.

BTW I've got Pacesetter LTs & Y-pipe and I haven't had that problem- which I'm glad of because the Y-pipe isn't coming off without some serious yanking- wish I'd had flanges welded on.

 

If ya put anti-sieze on ALL the slip together joints they will fall apart the next time.
I did that with stainless flat band clamps at every joint.

 

I have the same problem, but my happens at a certian throttle position and while sitting at a stop light witht he car in drive.

I have been trying to think of a fix for the past couple weeks and couldnt come up with anything besides motor mounts, thanks for the other idea guys

 

Too late now. I was in a hurry when I was doing it (always a bad thing when doing modifications), so now I'll pay the price. I'll probably get flanges welded on and get the rest of the exhaust welded, it leaks no matter what I do anyway. There's usually black marks on the header, and if I tighten it anymore I'll crimp the pipe and header together- already did that to one part of the exhaust, had to take it apart w/ an air hammer.

 

Is the pacesetter a 3" pipe too? I have a hooker i think ory with hooker longtubes and mine hits too. But im planning on going to a 2.5" exhaust setup. Will it still hit if i do? Is the headers the problem or the ypipe? I was told the ypipe was too big for clearence in the tranny crossmember so it would hit cause they couldnt bring it down any. But with smaller pipe i guess it would work out for me?

 

it is a 3" pipe but my problem isnt hitting the trans cross member but actually the ORY hitting the sub frame of the car

 

Put the stainless band clamps on it when ya take it appart the next time.
Sand,expand,grind to slip together.
They won't leak with the band clamps and they WILL come apart next time.
They are spendy(10-15 dollars a piece) but are worth it and can be reused for a lifetime if put back were they were.
I have 9 on the shop car that has a 2 x 3-1/2""Y" into a 4" out the back with a 4" x 17" shootout muffler.That SOB was fun to fit with all round tubing and up off the ground where ya don't drag the damn thing off.

 

Pacesetter is 3". 2.5" would give you an extra 1/4". But the pacesetter already has a spot on the driver's side that's pressed in. I take it the hooker one doesn't?

BTW you might want to check your trans mount as well since it's what controls the "angle" of the engine. Don't know how far the trans mount could be pulled up like that, just throwing it out there as an idea.

 

Sounds like fun, I'll keep that in mind. But I'll probably just get everything welded or flanged. I don't get along with exhaust clamps anymore.

I might do one strategic spot like you're saying just so I can still drop the exhaust easily if I have to.

 

No hooker doesnt have a dent on the driver side for that. And my driver side header hung up a lot higher than the passenger for some reason we couldnt figure out. Which is probably why it hit.

My ypipe/header hits on the floorboard really more than the trans crossbrace. But ill look into the bolts for it being too tight.

 

The flat band clamps 3" wide work good.

 

I was referring to the trans mount being "loose", allowing the engine/transmission to move around under throttle, causing the pipes to hit floorboard. A lot of people have had problems with their transmission smacking the tunnel w/ a bad trans mount. I don't know if that's what would happen, but I thought I'd throw it out there as a possibility. Those 3 mounts are the only things that position the headers properly, so it wouldn't hurt to check them. Mine are all poly and I've never had problems.

 

Oh, well ive had my transmission hit the floorboard before if thats what youre referring to. I will look into them being off which might be why the driver side header is up too high. But they shouldnt be, ive had bigger bolts driven through my tran mounts because i stripped the stock ones somehow to just a straight rod lol

 

yeah i have my exhaust flanged at the cutout in the back b4 the bend over the axle... came in handy when swaping the trans. i didnt really torque my y-pipe to the headers too much, i hope it will come off.

 

Don't waste your time wedging crap between the floorboard and y-pipe. Either pull down on the Y-pipe and have a hanger welded in, or do what I did...take the header and Y-pipe off, and crush the floorboard with a bottle jack.