• The Boss 429 used the same cylinder heads as your 1969 Lincoln.Out of Rubber image by JDsheely from Fotolia.com
  
  Introduced in 1968 as the "Thunderjet," Ford's top line big block boasted more cubic inches than any other V8 of the muscle car era--460 of them to be exact. But unlike their Chevrolet and Chrysler counterparts, these mountain motors were designed from the outset to haul heavy trucks and cars around town on a massive wave of torque. The 460's cylinder heads sacrificed a bit of top-end flow to enhance the motor's bottom-end torque.
  
  

Identification

• The 1969 Lincoln 460 used the same cylinder heads as the 429 performance engines used in Boss 429 Mustangs. You can identify the iron 460/429 head by looking at the casting number on the flat, horizontal pad just above the center exhaust port. These heads will use either casting number C8VE-A or C8VE-E.
  
  

Ports

• Intake ports define an engine's top-end power potential. The 460 uses slightly small ports that help to increase air velocity for low-end torque but limit top-end power potential. The round intake port measures 2.18 by 1.87 inches with a total volume of between 260 and 270 ccs. The exhaust port measures 1.99 by 1.3 inches.
  
  

Valves

• The C9VE head uses 2.09 intake and 1.65-inch exhaust valves.
  
  

Combustion Chamber

• The 460's heads use 75 to 77 cc combustion chambers that yield about 10.5:1 compression on pre-1972 blocks with standard pistons and 9.5:1 to 10:1 on later 460s. The combustion chambers are wedge-shaped (similar to the Chrysler 440's) with large quench pads. Still, the C8VE heads' very small combustion chambers make them a popular option for raising compression on the low-compression, low-performance engines that came later.
  
  

Emissions

• The C8VE head uses a smaller Thermac (thermacular pump) valve than those used on newer engines, but the Thermac passages aren't drilled for 49-state legal emissions as are the units used on later heads.
  
  

Rocker Arms

• The Lincoln's head uses self-aligning, 1.73:1 rocker arms on a cast-iron common rail, which is secured to the heads via 3/8-inch positive stop studs. If you want to use aftermarket roller rocker arms, you'll need to switch out the positive stop studs for a set of standard studs designed for a big block Chevy.
  
  

Valve Springs

• The C9VE head uses non-rotator valve springs with a 1.460-inch outside diameter and a 1.820-inch installed height.