Author Topic: Bullock's Power Service 429 Cobra Jet all iron, Q-jet 518 cubes  (Read 768 times)

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My427stang

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Bullock's Power Service 429 Cobra Jet all iron, Q-jet 518 cubes
« on: February 17, 2026, 11:37:40 PM »
This one is a genuine 429 Cobra Jet, original parts with pedigree.  Super fun to build, going in the original CJ car it's been in for decades, C-6, 3.25 gear.

Idle
https://youtube.com/shorts/jZz2oV-S5-I?si=YB18mzMxjy4MOM97

Dyno pull
https://youtube.com/shorts/Gc4m-BvIyY0?si=OydEO3EMpxq0N1cw

Performance Summary:
      Cubic Inches:  518            Dyno brand: Stuska
      Power Adder:  N/A             Where dynoed:  Dale Meers Racing, Buffalo, KY
      Peak Horsepower:  547 HP @ 5000
      Peak Torque:  640 @ 3600

Engine Specifications:

   Block brand, material, finished bore size, other notes: Factory 4-bolt 1971 429 CJ, 4.380 bore, ARP main bolts, CnC square decked, torque plate honed
     
   Crankshaft brand, cast or forged, stroke, journal size: SCAT cast 4.30 internal balance
     
   Connecting Rods brand, material, center to center distance, end sizes, bolts:  SCAT 6.800 I-beam 7/16 bolt

   Piston brand, material (cast, hypereutectic or forged), dish/dome volume, static CR: Racetec 34 cc 4032, 10:1

   Main Bearings, Rod Bearings, Cam Bearings brand and size:  Clevite rod and main bearings, Durabond cam bearings

   Piston rings brand, size, other notes: Mahle 1.5/1.5/3.0 mm

   Oil Pump, pickup, and drive:  Melling HV, Melling pickup, ARP drive

   Oil pan, windage tray, oil filter adapter:  Factory CJ oil pan, no tray, no filter adapter

   Camshaft brand, type (hyd/solid, flat tappet or roller), lift and duration (adv and @.050"):  Custom Bullock's Power hydraulic roller, 237 @.050 intake, .620 lift, 115 LSA on 108

   Lifters brand, type:  Morel standard travel

   Timing chain and timing cover: Cloyes 9-position roller, Ford cover

   Cylinder heads brand, material, port and chamber information:  Factory D0OE-R Cobrajet, slight bowl work, bronze guides, SI 2.25/ Ford Racing tulip 1.75, 5-angle intake, radius exhaust.

   Valve springs: Manley 22429-16, 160 seat, 400 open
 
   Rocker arm brand, type (adjustable or non-adj), material, ratio: Comp Steel roller

   Rocker shafts and stands, brand, material: Trick Flow rocker studs

   Pushrods brand, type, length:  Custom Smith Brothers 5/16, .116 wall call/cup oiling

   Valve covers, brand, type:   Original 1971 429 CJ cast aluminum

   Distributor brand, advance curve information:  Factory 429 Cobra Jet
 
   Harmonic balancer brand:  Rebuilt factory 1971 Cobra Jet

   Water pump brand, type (mechanical or electric):   Factory Ford restored/rebuilt

   Intake manifold brand, material, porting information:  Factory Ford iron Cobra Jet

   Carburetor(s) brand, type: Factory 1971 Ford Quadrajet 780 cfm

   Exhaust manifolds or headers brand, type:  Dyno headers
« Last Edit: February 22, 2026, 01:04:40 PM by My427stang »
---------------------------------
Ross
Bullock's Power Service, LLC
- 70 Fastback Mustang, 489 cid FE, Victor, SEFI, Erson SFT cam, TKO-600 5 speed, 4.11 9 inch.
- 71 F100 shortbed 4x4, 461 cid FE, headers, Victor Pro-flo EFI, Comp Custom HFT cam, 3.50 9 inch

price5113

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Re: Bullock's Power Service 429 Cobra Jet all iron, Q-jet 518 cubes
« Reply #1 on: February 23, 2026, 03:20:02 PM »
Really nice results! With that much TRQ the owner is going to have a "permeant" smile! Are headers being used in the car or manifolds?

My427stang

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Re: Bullock's Power Service 429 Cobra Jet all iron, Q-jet 518 cubes
« Reply #2 on: February 23, 2026, 10:48:59 PM »
I believe he is planning the original manifolds, we cammed it for that, but even so, it'll take some big numbers away at the peaks.

All original externally though, and add a bunch more torque and power, should pull much harder than Ford intended :)
---------------------------------
Ross
Bullock's Power Service, LLC
- 70 Fastback Mustang, 489 cid FE, Victor, SEFI, Erson SFT cam, TKO-600 5 speed, 4.11 9 inch.
- 71 F100 shortbed 4x4, 461 cid FE, headers, Victor Pro-flo EFI, Comp Custom HFT cam, 3.50 9 inch

e philpott

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Re: Bullock's Power Service 429 Cobra Jet all iron, Q-jet 518 cubes
« Reply #3 on: February 24, 2026, 10:21:45 AM »
Those manifolds are pretty decent compared to most other Ford manifolds , those guys that run in the F.A.S.T class port the dickens out of those manifolds , it'll be a nice sleeper