Author Topic: '67 2.5" H pipe exh. kit w/o mufflers? (Read 460 times)

Jonk67 · « **on:** August, 20, 2009, 08:44:29 AM »

Hi all, well I started searching to find what I feel will work best for me. Looking for a kit with 2.5" pipes and an H pipe for my '67 Coupe. I like the Magnaflow SS kit but don't want to spend that much, doesn't have to be SS and I prefer the H over the X pipe for sound and ease of removal in case the trans ever has to come out. I want to go with mandrel bend and haven't found a local shop that does mandrel in house (Nashville area) so I figured I could get a kit and add my mufflers and have a shop mate them to my headers/pipes.

I've got MAC long tube headers and ~2' of header pipes made by MAC to bolt on and get me next to the trans., 333, an AOD is going in and I plan to add the non polished Magnaflow mufflers. I also want to cut my exh. turndowns to be level with my rear valence so they're kind of hidden/tucked (nonGT valence) as they were when I got the car.

Who sells a full kit w/o mufflers 2.5" w/H pipe? I see flowmaster has a muffler back kit 15807 http://flowmasterdirect.com/product.php?productid=43479, I figure that would take care of the mandrel bends part and I could just get a local shop to fab the H pipe and line it all up. Any better ideas or suggestions to get what I'm looking for? I've looked at Magnaflow, DynoMax (no classic kits offered), Thrush ($250 w/Thrush mufflers), Summit has a kit w/mufflers for $180 but no H pipe so I'd have to add it and don't know how well it fits.
I'm leaning towards the Flowmaster rear pipes, magnaflow mufflers and let the local shop mount/tweak it all to my liking, I want a nice tucked custom fit.
Thanks, Jon

daveSanborn · « **Reply #1 on:** August, 20, 2009, 10:16:41 AM »

Unless you have your heart set on stainless steel, most muffler shops that specialize in installing FlowMaster/MagnaFlow type exhaust kits can do a pretty good job bending up custom pipes from front to rear.

FYI, the exhaust pipe "sticks" being used these days are chemically coated (aluminized???) and look pretty decent for years. They're also only about $20 per 10'.

The pre-bent kits IMO are over-priced for the "do-it-yourselfer" who doesn't want to bring the car to a muffler shop.

blue65coupe · « **Reply #2 on:** August, 20, 2009, 05:37:31 PM »

I would go to a shop also. I contemplated the kit for mine but let the pros do it. I think it ran me $325 from headers back using regular turbo mufflers. It was "bent and tucked" as you are describing at the rear valance. That cost also included them putting in an H-pipe and welding in my cutouts.

Jonk67 · « **Reply #3 on:** August, 20, 2009, 07:13:42 PM »

I'm just contemplating how much restriction I may get from a shop bent system vs. a mandrel bent one, doesn't have to be SS, I have yet to have an exh. system rust away on me so aluminized is fine. I've read that a mandrel bent is 2.5" throughout and I think the manual bent ones narrow down to ~2" where they have to kink bend them in the normal muffler shops, especially over the axle where it's basically 4-90* bends in a 2-3ft. section.

I have spent extra to make sure my motor breathes well with Demon Jr. 625, port matched Weiand Stealth, AFR 165's and MAC longtube headers, I'd hate to restrict it at any bends down to 2" if that is the case. Opinions?
Thanks, Jon

daveSanborn · « **Reply #4 on:** August, 21, 2009, 04:34:37 AM »

Quote

Opinions?

You're correct. Shop bends will likely NOT be mandrel bent and will reduce the diameter significantly on sharp turns.

blue65coupe · « **Reply #5 on:** August, 21, 2009, 05:57:28 AM »

If you want mandrel, you'll probably have to order the kit unless you can find a shop to do it. Like Dave said, most do not. The question I have (and had) was how much will a shop bend really restrict the flow? From what I see in your post, you won't be happy unless you have a mandrel bent system. There will always be that question in your mind. Buy a kit.

Jonk67 · « **Reply #6 on:** August, 21, 2009, 08:07:29 AM »

Thanks, as Dave said "Shop bends will likely NOT be mandrel bent and will reduce the diameter significantly on sharp turns" and from what i've read a 2.5" pipe narrows to 2" or > due to the ripples on the inside of the bends and curving in of the outer side of the bend. I was initially trying to see if anyone had located a kit that was 2.5" mandrel w/o mufflers and w/H pipe.
Thanks, your replies helped me narrow my choices,
Jon

lethal289 · « **Reply #7 on:** August, 21, 2009, 04:13:41 PM »

Just my .o2, but the magna flow kit was worth every penny. It bolted up nicely with the exception of having to tweak the brake line bracket on the rear axle.

Starfury · « **Reply #8 on:** August, 23, 2009, 01:46:16 PM »

Why not order the individual mandrel-bent segments from Summit and take them to the muffler shop? One of my buddies ordered a bunch of pieces for his C10 and welded them up himself. The end result looks great and fits pretty damn well.