Joined: Thu Mar 22 2007, 08:13AM
Location: In the workshop
Posts: 1063
I've been looking at HP exhaust manifolds lately. Do any of you know how easy it is to get hold of them, and fit them to a C-body? Are they a direct bolt on to a tti exhaust, or does it need modifying for them to fit?
Joined: Tue Oct 11 2005, 11:01AM
Location: Central Iowa
Posts: 227
I just did this to my 70 300, 440. The manifolds just bolt right on. There is a specific driver side manifold for the "C" bodies, that has a different tail end twist. I believe tti will make their pipes to fit the manifolds that you have, and you have to give them your manifold cast part numbers for them to do this. I waited until my existing exhaust needed to be replaced, then exchanged the manifolds, and had new pipes installed to fit the new manifolds at a local shop. They even put a cross over tube in place. Any existing exhaust pipe work will need to be modified if you are going to keep them, and install the HP Manifolds. That is why I waited 4 years for the existing exhaust to rot away.
Joined: Wed Dec 21 2005, 07:34AM
Location: indiana
Posts: 791
x2 on what Paul said, plus you need special sleeve nuts for some of the studs, and it varies with manifold.
The angle, location, and even the flange 'clocking' can vary amongst manifolds, so TTI headpipes are pretty application-specific.
Unc Joe: Maybe Hedman shorty headers would be a better choice? I have a set to put on my 300L so I could give feedback if there are any fitment issues near that funky driverside motormount.
Paul: I also have a 70 300 TNT, and I contacted TTI several years ago about headpipes for teh driverside manifold (they list a 69 but not a 70, and I suspect the only difference is the heat stove). They didn't answer. I waited a few months, tried again, and still never got an answer. I'd say you were wise to go teh muffler-shop route.
And now my small rant with TTI: Based on installations I have done on 3 different C-bodies, I have not found TTI stuff to fit as nicely as it should for all the raves people give them. I found the headpipes hang unevenly side-to-side, which then throws the H-pipe off also. The headpipes I have seen wrap around the torsion bars instead of taking a straighter shot between the frame and T-bar and straight back to the crossmember cutout -- so their stuff has more bends than required. The location of the rear tailpipe hangers does not match the location of any of the existing holes in the rear framerails, so new holes must be drilled (which is a PITA near the gas tank on the driverside ).
For the record, I have home-brewed X-pipes on 2 cars (using Summit universal X-kits) and although my pipes have to be spliced together and aren't as pretty, my pipes fit nicer and have better ground clearance.
If I had never done any of my cars myself, I'd probably be tickled with TTIs stuff, but due to the experience I've had (on 3 separate installations) I guess I'm not real impressed for professional products made with a CNC mandrel bender. !zzz
<span class='smallblacktext'>[ Edited Fri Oct 03 2008, 10:40AM ]</span>
Joined: Wed Jun 06 2007, 04:17PM
Location: Vancouver
Posts: 211
excuse my dumbness, but how do I tell if my existing manifolds are HP or not? When I bought the car, the seller (who was no expert) said it was an HP car - its a '68 Newport HT with a factory 4BBL and dual exhausts...
Uncle Joe wrote ... I've been looking at HP exhaust manifolds lately. Do any of you know how easy it is to get hold of them, and fit them to a C-body? Are they a direct bolt on to a tti exhaust, or does it need modifying for them to fit?
The drivers side HP manifold is relatively easy to find and not very expensive, as it is a C body only application. The passenger side manifold is also avalable, however will cost you a lot more money because it is also used on the B bodies, and those guys snatch them up pretty quickly. You can usually find both on Ebay, three drivers side manifolds sold last month for only $25 each, but look to spend about $60for the drivers side and up to $150 for the right side. I prefer using HP manifolds rather than troublesome headers which almost always develop leaks and sometimes crack. With the Maniolds you just bolt them on and forget about them.
These manifolds bolt right on, but you will need to get the special long sleeve nuts for the C body (try Mancini racing, they sell a kit specifically for the C body). I recently installed some HP manifolds on a friends Satellite, and we carefully replaced all the old rusty and broken studs, using thread sealer to prevent any coolant leaks because some of the studs go into the water jacket.
I have an aluminized TTI system and absolutely love it! It was expensive, but the quality is much better than what you can get from your local muffler shop--smooth mandrel bends. Every muffler shop welded together exhaust system I have seen has eventually rusted out at the welds. My TTI system has been on the car for three years and it still looks like it is brand new. I just called them up and told them what manifolds I had, and they made the down pipes to match and shipped the system out that week. I also had them make my down pipes a little bit shorter: not lengthwise, but vertically, because the 383 is shorter and so the manifolds sit 3/4" lower than the 440 ones do. (I put an off the shelf TTI system on a 70 Polara with a 383, and the down pipes hung a bit lower than I liked, because they are made to fit either engine and so have to be taller to fit the 440s.
I too have installed more than one of these systems, and never had any trouble (just follow their directions and install the pipes from the REAR moving forward). The 2 1/2" systems fit a little easier than the 3" ones because there is more clearance. It is true that TTI could have run the drivers side pipe between the torsion bar and frame, but the passenger side won't fit that way when using the HP manifolds, there is just not enough room. If your car has a single pipe system, then you will have to drill a few holes in the rear cross member on the side that didn't have a pipe, to bolt on the hangers, but it is not difficult. <span class='smallblacktext'>[ Edited Fri Oct 03 2008, 12:51PM ]</span>
tonyvan wrote ... excuse my dumbness, but how do I tell if my existing manifolds are HP or not? When I bought the car, the seller (who was no expert) said it was an HP car - its a '68 Newport HT with a factory 4BBL and dual exhausts...
The HP manifolds are "curvy" and stick up almost as high as the top of the Valve cover. The LOG maniolds are just that--straight logs. see pics:
<span class='smallblacktext'>[ Edited Fri Oct 03 2008, 05:14PM ]</span>
Joined: Thu Mar 22 2007, 08:13AM
Location: In the workshop
Posts: 1063
As far as I can figure things, there are 3 different pairs of HP's. C-bodies use casting #2951865 and #2899879. The question now is if tti make a pipe for these. I know from when I got my 2 1/2" system they wont do them for all manifolds. Unless of course they will now.
FuryFan: I cant use Hedman shorty's due to local laws.
Try this site that lists all the part numbers for the various exhaust manifolds. The HP ones in my previous photo will fit any C body from 67-73,(rt side #2806900, left side #2863409, and TTI will make pipes for these manifolds)) but I don't know about cars made earlier. (I also think the HP manifolds didn't come out until 68', but I have been wrong on more occasions than I like to admit)