Today was the first day I had the car out. I was drivin it around a little, enjoying the new found power. Engine runs great, good oil pressure, good temp, good voltage, and no leaks.
Now here's the problem. I put the hedman longtubes on, and thought I had a good fit. With this new setup, I'm feeling a little more vibration throughout the car, but I also have brand new motor mounts and that's what I account most of the vibration too. The other part is that the driver side, even though it seemed to fit, it was still touching the A arm mount. This is creating a vibration in on the header bolts, and they are coming loose fairly easily. Tomorrow I'm going to try to get some header bolts that come with the highgrade lock washers. If that doesn't work I dont' know what I will do.
Those with these headers, did you clearance the header to the point of being able to bolt them to the heads and still not touch anything (A arm mount or frame)?

Ryan

 

The problem is only on the Driver side header. The passenger side is fine.

 

You have to grind back the driver side control arm mount that is more than likely where the vibration is coming from when you put the washers in go ahead and pull the header and cut the mount back the put the header back on.

 

There are two things wrong with doing that.
1. I didnt' wanna have to cut the frame
2. There was a couple things that had to be off the car in order to get that header it and out (oil pressure sender and most of the spark plugs on that side)

If I have to, I will, but I'm wondering if there is anyone out there with these headers fitting in their 3rd gen without any frame modification. As much as I love the power from the longtubes, I might end up going to shorty style if I decide to lower the car.

More suggestions please

Ryan

 

i don't know....i had to extensively cut my crossmember to get those headers to fit. So much that i'm thinking of either welding in some plates or possibly going to a tubular crossmember....but then i'll want to go turbos so who knows.

 

didnt have to do any modifications to fit hedman lt's in a buddy's car. although dont plan on lowering the car much

 

Dude the plugs are easy with the headers as far as the oil sender mine is in a different location and the part you have to grind off is the back corner of the front control arm mount just make sure you grind enough off before you put everything back together but if not you can trim it up a bit with a dremel and a cutter by prying the header away but be careful cause on slip can mean a hole in the tubes.

 

The part of the side of the frame that must be trimmed is not load bearing and will have little to no effect on the strength of the frame. This is unavoidable. A few unlucky people such as me have tubes resting on the top of the frame. If so you may want to just dent the #4 and #8 primary. Check out my install https://www.thirdgen.org/techbb2/sho...ghlight=hedman

You should never have the headers touching any part of the frame as this will cause the things your talking about here, and also with a TPI, TBI, or ?CC quadrajet? cars this may cause false knock, and kill performance. My guess is that you did not trim the frame on the side and the driver side header is installed crooked. It is probably not touching the head squarely. If this is true, locking bolts will only keep the bolts on but still allow it to blow out the gaskets.

 

Notched the A arm mount today and I still have a little leak. Even using a set of Copper gaskets. I had dimpled the second from the front to stay off the frame, but I didn't do it that much cause it didn't look like it would hit once I notched the A arm mount. The header is also hitting on the last tube on the top part of the A arm mount, but not enough to need the frame notched. I'll get the header out and dimpled those two spots a little more. I'm hoping that will take care of it. How much clearance is enough? 1/4 inch? 1/8 inch?

Ryan