I have a set of Dyno Don's headers that I'm trying to install after head and cam swap. They just don't want to mate to the head, specifically at the top. I poked around here and found that changing the motor mounts could help, well not in my situation.

My next idea is to notch the K-member for them to fit, as it seems thats where they are hitting. (See second pic, Tube to cylinder #3) Any ideas suggestions before I grind away? Has anybody else had to do this?

 

Have you given Don a call, maybe poly mounts will give you the necessary lift you need.

 

Hadn't thought about polymounts, but I'll try to get a hold of Don.

Clarification, the problem is only for the driver's side header.

 

definitely looks like the motor mounts are shot and the engine is sitting a little low.

or hammer the k-member a little where it hits and maybe that will be enough for now?

 

i had to notch my k-member. you can find pics here
https://www.thirdgen.org/forums/exha...-3rd-gens.html

 

Something must be tweaked, I am not aware of that problem before.
For sure try the mounts.

 

I did change the driver side mount, just to see if it would help but it didn't, the photos were taken with the new motor mount in place. Would you guys suggest trying a different set of mounts?

Don brought up a good point, is there any way to find out if the frame and/or k-member is bent/tweaked? All I can think of is having it towed to an alignment place to see if the front wheels can be aligned.

Another idea I had was to jack the motor up, install the headers, then slowly lower to see how far down it goes before it hits.

Worst case is I'll notch the k-member if necessary as FueledSoul suggested.

By the way, thanks a lot guys, I'll keep you posted.

 

UPDATE: Today I lifted the block, installed the driver side header, then lowered the block back down. Saw that the motor mount holes on same side didn't quite match up (between 1/8 & 1/4 inch off center). Lifted motor back up and saw scratches on the header coating, and the K-member, but no dents. Lowered it back down and wrestled the motor mount bolt through, but it did go in.

Would you guys leave this as is, the header is literally touching the K-member at this point, but no way of telling how much pressure between the two.

Thanks in advance.

 

By the pics, it looks close to a brake line too. Not sure how the heat will effect it. If it's touching, personally I wouldn't leave it like that. Seems to me it would vibrate like crazy.

 

I did move the brake line, but I should move it more since I'll probably end up hammering or cutting the k-member anyways.

 

I would do some hammering if you can or if you have to grind it, you will need some room for when the engine twists and shakes.

 

Get some poly motor mounts so that the motor isn't sagged down, and put them in. Problem should be solved. If you just leave the header rubbing the frame, the coating will chip off, and eventually the tube will wear through or crack.

 

He said he put a new motor mount on that side. I would find it hard to believe Dyno Don's headers require poly motor mounts. It must be something else.

 

ill be installing my motor in the next week or 2, ill let ya know how my headers fit, i have the same

 

Any new developments on this? I just put on some Hedmans and have the same exact clearance issue on the driver's side. I got the header to mount flush with little or no leaking but the primary is clearly resting on the K-member. Throughout most of my RPMs, I have no issue with vibration, but when I come to a stop and the RPM's hit around 600-800, it is like sitting in a vibrating chair! I removed the driver's side motor mount bolt and jacked her up slightly to see when clearance was made and it didn't take much. Did anyone have any luck with the poly mounts raising the motor a noticeable difference?

 

I ended up pulling the whole motor for an entire rebuild. I plan on buying poly mounts to see if that will provide clearance I need. If that doesn't work, I'll cut up the K-member. Let us know if you end up resolving your problem.

 

For me installing poly motor mounts raised my engine considerably. So much so that my y-pipe hit my floor pan and my strut tower brace wouldn't clear my plenum. Went to back to new GM rubber mounts and life is good. So if your goal is to raise the motor, try the poly mounts. I'd say it raised my motor at least 1/2".

 

I'll be running a T-56 trans, so hopefully I won't have the y-pipe/tranny clearance problem. I'm banking on getting the right clearances.

 

After an engine rebuild, I got the headers to fit with no issues. Although I had a new motor mount on the side with the clearance issue, the mount had probably slid down within the shell. Also, come to find out I had one poly mount on the passenger side of the car. I went with new poly mounts on both sides and all is well now.