LS3 down pipes

[House Money]

Working on my exhaust and wanted to run this by the forum. FFR includes spacers to go between the headers and the down pipes, they also include two sets of metal gaskets. My concern is the length of the bolts they provided - 30MM - and when everything is stacked up there are only about two threads left to engage the header. 128252

I know the gaskets will crush some - maybe 50%? - so just for mock-up purposes I removed one gasket and checked again and there are still only about three threads: 128253

Do you think 3, or possibly 4, threads are enough? I'm not comfortable with it so I bought some 40MM ones but all my hardware store had were stainless steel and were $5.49 each!!

For now I think I'll assemble the exhaust using the short bolts but can change them out based on what feedback I get.

Gary

[bnelson]

Working on my exhaust and wanted to run this by the forum. FFR includes spacers to go between the headers and the down pipes, they also include two sets of metal gaskets. My concern is the length of the bolts they provided - 30MM - and when everything is stacked up there are only about two threads left to engage the header. 128252

I know the gaskets will crush some - maybe 50%? - so just for mock-up purposes I removed one gasket and checked again and there are still only about three threads: 128253

Do you think 3, or possibly 4, threads are enough? I'm not comfortable with it so I bought some 40MM ones but all my hardware store had were stainless steel and were $5.49 each!!

For now I think I'll assemble the exhaust using the short bolts but can change them out based on what feedback I get.

Gary

LOL. I probably have over $300.00 in SS nuts and bolts from Ace Hardware. I just couldn't see using some of the things they provided that did not really fit right or were going to be fatality to the elements (rust). And then of course in building our own versions....things change. If you know its not right...spend the $12 bucks :)

[House Money]

Well I had to use the longer bolts I bought as I couldn't even get the short ones to engage the threads in the header flange.

But now I have another question. I noticed that the down pipes are different, one is longer than the other, I also noticed the header flanges were not the same, one was higher than the other.So the short pipe went on the lower header flange and the long one on the flange that was shorter, that left me with both ends of the down pipes just about exactly equal at the 4-both flange ends.

What has me confused is this 4-bolt spacer: 128264

It is 1/2" thick and they sent an extra metal gasket as well. So has anyone else received this? And if so, where did you install it? It is not mentioned in the manual. I compared all the remaining pipes and there are all they same lengths. I received two boxes of exhaust related parts, one appeared to be LS3 specific and the other truck specific, this spacer was with the truck components.

[House Money]

Well it turns out that spacer goes on the drivers side between the down pipe and the next pipe. Man, the right side sure it tight to the floor at the end of the down pipe, I had to grind quite a bit off both the flanges. Seems like that down pipe could be a little longer or angled towards to inside some to allow some clearance.

[House Money]

An update: I had mentioned that the right side pipe was hitting the floor, well the muffler was in no way going to fit so I contacted FFR and was told they had redesigned the down-pipe. They sent me one and I should have it in about a week, I'll update this again when I get it.

Gary

[House Money]

Got the new down pipes and installed the right side, it no longer hits the frame and now the muffler also fits. One thing I thought was odd though: If you are redesigning the pipe, why not add enough extra length to allow the 1/2" spacer at the header collector to be eliminated?

Gary

[McGuyver]

Thanks for posting. I am a ways off but will have to cross this bridge eventually. My kit was delivered in January, did FFR mention just when they updated the pipes?

[House Money]

They did not, but I got the impression it was recent. Let me know if you want any measurement(s) so you can compare to what you have.

[McGuyver]

Hey Gary, I made it to this stage, ran into the same problem - right side down pipe square flange was interfering with the floor. I checked with FFR and they sent out revised downpipes. I tried them on today and same issue. Upon close inspection the new pipes are identical to the old pipes. I will check with FFR again on Monday to see if by chance they sent me the old version.
I measured from inside flange around the bend to inside of the flange on the left side and got ~ 12.5". This one fits ok if you use the spacer. For the right side the measurement was about 13.75" This one hits the bottom of the floor with one spacer, another spacer and it might work. I just don't like stacking a bunch of spacers...
If you get a chance put a tape on yours the best you can to see if they match up to what I have.
Thanks
Ed

[House Money]

Hey Gary, I made it to this stage, ran into the same problem - right side down pipe square flange was interfering with the floor. I checked with FFR and they sent out revised downpipes. I tried them on today and same issue. Upon close inspection the new pipes are identical to the old pipes. I will check with FFR again on Monday to see if by chance they sent me the old version.
I measured from inside flange around the bend to inside of the flange on the left side and got ~ 12.5". This one fits ok if you use the spacer. For the right side the measurement was about 13.75" This one hits the bottom of the floor with one spacer, another spacer and it might work. I just don't like stacking a bunch of spacers...
If you get a chance put a tape on yours the best you can to see if they match up to what I have.
Thanks
Ed

Hi Ed, I measured my right side pipe and get about 14.5 or maybe even 14.75", so I think you are correct that they sent you the same pipes you already have.

Gary

[McGuyver]

Thanks for checking, I will definitely be following up with FFR on Monday or after the holiday if they are out.