I just got around to fitting Dyno-Don's headers and y-pipe. The passenger side header touches the frame when installed, and it seems like the y-pipe is pretty far over (tire rubs on the pipe at full lock and it's essentially up against the pinch weld). I've read that having the clamshells on the wrong side can locate the engine incorrectly, could this be what's happening? Is there an easy way to check this before I have to go to the exhaust shop to get the y-pipe modified?

 

An update: Looks like the clamshells are probably on the right side. The driver's side has the smooth edge while the passenger has the edge with the two "recessions" on the corner. Any ideas on why the fitment seems off are appreciated.

 

So I verified the number on the passenger side and it corresponds to the passenger side part number. So the clamshells are on the right side. Would it be possible to move my engine towards the driver side somehow? Will loosening the mounts and sliding them give any room, or is the tolerance too tight for it to slide without slotting the holes? Maybe a shim on the passenger side, but that might raise the angle and make it hit anyway.

 

I had the same problem with my headers. Seems Im one of the few. Correct gm clamshells and oe rubber motor mounts from gm. Still didnt fit correctly. Email Don.

 

They are custom made headers so the fit is going to vary from car to car and from header to header. I installed 2 sets and both sets hit on the drivers side of the engine cradle. The set in my car was the worst,... I had to cut/notch the engine cradle in order to install my DD set-up. The OEM Motor mounts were near new and the clam-shells were on the correct sides. I remember Darrens set-up hit on the pass side - might be the only time I heard of a pass side problem till now.

I'm sure that what I dealt with isn't what your dealing with, but they similar in that you'll need to figure out some way to make them work. There are 3 things I can think of 'quick' that MIGHT help.

Poly engine mounts,..... These will raise the engine evenly on both sides. Not sure how much - but the engine WILL sit a little higher.

Motor mount spacer,..... Again, this will raise the engine. Be sure that Triple check the clams are on the correct sides and add a spacer to both sides to keep the engine sitting 'even'

* I would try and avoid Poly mounts AND spacers together. Just one or the other,... Spacers would be FAR easier to install than Poly Mounts !

Thinner header gaskets,..... I used Earls and they are pretty thick, other brands might be thinner and that would bring the header closer to the engine and away for the frame rail/ cradle.

Last, Contact Don. Since the headers are not installed yet it might be reasonable to ship them back to him for assessment or possible replacement. You won't know what kind of help he might be able to provide you with unless you ask.

Another thought: Don't let the cat-back interfere with how the Y pipe fits the headers ! There is just 1 place the Y-Pipe is going to go,... and that's where the headers allow it to go. If your car already have an existing cat-back installed....... don't connect the Y-Pipe to the car back until everything up-front is OK & completely installed. This is true for ANY exhaust; The new headers and Y will almost NEVER land in the same place as the old parts that were removed. Get the headers and Y final installed and let the end of the Y-pipe fall where it will, then make any needed adjustments to the Cat-to-Y connection and or the exhaust hangers so the back of the exhaust fits to the front,... not the other way around.

Good Luck !

 

I ordered a set of spacers so we'll see how that works out. There's three sets of sizes so maybe some combination of passenger/driver spacers will raise and angle the header enough to have clearance. It's almost like the entire engine is shifted too far to the passenger side compared to the cars Don tests the header fitment on. I may just see if I can get the Y-pipe modified just for insurance (having the outside pipe closer in won't hurt anything if they do it right).