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#61
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Waited several years for the long branch round port manifolds. Finally just had to give up. Was pretty sure I would never live long enough to see them. Unfortunately, the D-port version is a poor compromise for the round port ones. Giving up substantial torque and HP with the D-port ones. After getting the "they are almost ready, and they are on the way to the machine shop", story for several years, a decision to give up became easier and easier. If the Pontiac hobby needs a reason why so many of our beloved cars end up with LS power, this is why. Takes allot of dedication and patience to stay Pontiac powered.
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#62
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Still waiting for my oversized D ports and 3" downtubes and X pipe.
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72 lemans,455 e-head, UD 255/263 solid flat,3.73 gears,,,10" 4400 converter,, 6.68 at 101.8 mph,,1.44 60 ft.2007 (cam 271/278 roller)9"CC.4.11gear 6.41 at 106.32 mph 1.42 60 ft.(2009) SOLD,SOLD 1970 GTO 455 4 speed #matching,, 3.31 posi.Stock manifolds. # 64 heads.A factory mint tuquoise ,69' judge stripe car. 8.64 @ 87.3 mph on slippery street tires.Bad 2.25 60ft.Owned since 86' |
#63
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#64
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I bought a set on EBay last year when I bought my Speedmaster heads just in case I was going to build a engine for my 69 bird.Never built a round port engine.Tom
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#65
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Agree that nearly anything is available at some price. When you can buy a set of new aluminum heads for less than the cost of a used set of iron exhaust manifolds, you can begin to see the problem for many. Custom headers are a no better option for many body styles. Only quote I got was $2200.00 for mild steel custom headers for my 62 Catalina. Mild steel. 9 month to a year wait. IMO round port iron exhaust manifolds are the second most severe log jam in the aftermarket Pontiac industry. 1. Iron replacement head for D-port 2. Iron Ram air exhaust manifolds, round port severe, D-port somewhat 3. Cam cores.
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#66
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Just curious, why do you think there needs to be replacement D-port iron heads? IMO, the 70 #64 heads would be the best option for a 400 and 71 #96, the best for 455 using the factory style flat-top piston, and those heads are getting fairly expensive and hard to come by. But a lot of people seem to be rebuilding with the aftermarket dished pistons which allow use of all the high compression D-port heads for rebuilds. Anyway, just curious, I know you know your stuff through and through. My #1 would be tri-Y headers like HO used to make.
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#67
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Don't want to derail this thread. Simply feel a iron replacement head for the most Popular Pontiac engine configuration would be a big seller and a great option vs aluminum or rebuilding old, poor flowing iron cores. Back to topic, sorry for getting off course.
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#68
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I don't understand why some people/vendors/manufacturers can't tell the truth about status/expected delivery. Stringing along customers by telling them fabricated (or at least highly optimistic) timelines gets old and makes the customer lose confidence in the integrity of the individual/company. I get the previous COVID supply chain issues and that they are basing production on received orders and don't want anyone to cancel. We're all big boys/girls that can handle the truth and/or make alternative decisions. Can't make that decision without accurate information.
So glad I got my oversized D ports, downtube and X pipe setup from them before the fiasco started, but even then Paul gave me a delivery date that was 2 months earlier than the actual arrival date.
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1970 GTO (Granada Gold) - 400 / TH400 Last edited by vertigto; 11-09-2022 at 03:00 PM. |
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#69
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round ports
same experience here.
I am so glad I got my oversized round ports apparently just prior to this shortage problem. I feel real lucky here! at the time I recall contacting several times informed of delays. agree, would rather be told straight up of why and when. |
The Following User Says Thank You to JUDGE3 For This Useful Post: | ||
#70
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I'm "SUPER" glad I bought my super long branch 3" outlet manifolds in 2004!
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#71
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You are lucky indeed. Recent dyno testing on my Superflow engine dyno showed a 28ft. lb. loss AVERAGE from 3000-6000 RPMs between really lousy 1 5/8" tube headers and stock reproduction long branch D-port iron manifolds. No other changes. This was a 468 Cu. In. engine. The iron manifolds just can't move enough exhaust out. So the worst tube headers you can put on are much better than the stock iron long branch ones. A smaller displacement engine may do better with them. Largest engine to use them was a 428 from the factory.
Last edited by mgarblik; 11-09-2022 at 08:25 PM. |
#72
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HP loss
My factory RA IV manifolds gave up 26 ponies to 1 7/8 headers without even trying to trying to max out the header calibration.
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#73
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Maybe this is a source for round ports if someone is in a hurry:
https://the-speedshop.myshopify.com/...haust-manifold |
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#74
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There is a tech article on SD website. Testing was done by Dave himself. Pretty cool deal.
I wish Dave would update his website.
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1977 Black Trans Am 180 HP Auto, essentially base model T/A. I'm the original owner, purchased May 7, 1977. Shut it off Shut it off Buddy, I just shut your Prius down... |
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#75
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Quote:
https://www.sdperformance.com/moreTech.php?newsID=39
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1970 Formula 400 Carousel Red paint on Black standard interior A no-engine, no-transmission, no-wheel option car. Quite likely one of few '70 Muncie three speed Formula 400's left. 1991 Grand Am: 14.4 @ 93.7mph (DA corrected) (retired DD, stock appearing) 2009 Cobalt SS: 13.9 @ 103mph (current DD; makes something north of 300hp & 350ft/lbs) |
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#76
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I see the 2.25" '68 and up D port version back on eBay.
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#77
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Any new news from rare on How the manifolds are going?
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72 lemans,455 e-head, UD 255/263 solid flat,3.73 gears,,,10" 4400 converter,, 6.68 at 101.8 mph,,1.44 60 ft.2007 (cam 271/278 roller)9"CC.4.11gear 6.41 at 106.32 mph 1.42 60 ft.(2009) SOLD,SOLD 1970 GTO 455 4 speed #matching,, 3.31 posi.Stock manifolds. # 64 heads.A factory mint tuquoise ,69' judge stripe car. 8.64 @ 87.3 mph on slippery street tires.Bad 2.25 60ft.Owned since 86' |
#78
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12.24/111.6MPH/1.76 60'/28"/3.54:1/SP-TH400/469 R96A/236-244-112LC/1050&TorkerI//3850Lbs//15MPG/89oct Sold 2003: 12.00/112MPH/1.61 60'/26"x3.31:1/10"/469 #48/245-255-110LSA/Q-Jet-Torker/3650Lbs//18MPG 94oct Sold 1994: 11.00/123MPH/1.50 60'/29.5"x4.10:1/10"/469 #48/245-255-110LSA/Dual600s-Wenzler/3250Lbs//94oct |
#79
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#80
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