STAGE 2 IMPRESSOR KIT
IMPRESSOR KIT
STAGE 2
CJ 428 Hydraulic Cam Adds 35 Horses -(Except "GT" 390's)
Now that you have big doors on top, let's do some remod\-eling illside. ("GT" 390 owners can sit this one out. You already have the CJ 42{I cam and wdve train pieces inside.) ()wilers of standard 390 4V's, however, call get an additional 35 horsepower @ 5000 film with 42,1 CJ HYDRAULIC CAM C6OZ.6250-B. This o1d smoothie works equally well with sticks and automatics.
OTHER MODIFICATIONS REQUIRED
Installation of the 428 CJ production cam requires some valve train modifications to standard 390 4V's. (You "GT" 390 owners can continue watching, as you already have these pieces as regular production parts. )
VALVE SPRING AND DAMPER ASSY. C8AZ-6513-B (16 req'd) should be installed to keep valves down where they belong at higher rpms. These CJ 428 springs will resist valve float and give proper spring pressure at installed height of 1.82".
RETAINERS C3AZ-6511-A (16 req'd) and KEEPERS B8A-6518.A (32 req'd) from the 428 CJ should also be installed for high perfornmnce operation.
NOTE: With installation of the above parts, the standard 390 4V is now identical as the "GT" 390. No additional reference to differences will be made in this kit.
TAPPETS C8AZ-6500-B (16 req'd) should be installed if originals have the 0.002" crown worn flat at the cam end and thus need replacement. These hydraulic lifters are from the 428 Super CJ and feature a high strength socket for improved high performance durability.
PUSH RODS C4TZ-6565-D (16 req'd) must be installed to maintain correct valve train geometry. They are 0.060" shorter than stock push rods. The shorter push rods must be installed because of the 0.030" that must be milled off the 428 heads in Stage 4 and the 0.020" thinner head gasket used to obtain a 10.7:1 compression ratio. This decreases distance from the cam's center to the rocker arm shaft's center by 0.050".
NOTE: 1966-67 ENGINES ONLY
CRANKSHAFT DAMPER C6AZ-6312-A nmst be installed on 1966-67 engines to maintain engine balance at high rpms. The new damper also requires TIMING POINTER C9AZ-6023-A (on 1966-67 engines without air conditioning) or TIMING POINTER C5AZ-6023-A {on 1966-67 engines with air conditioning) and ALTERNATOR ARM C7AZ-10145-A (on 1966-67 engines with air conditioning or Thermactor).
DUAL POINT DISTRIBUTOR
Since hydraulic cam C6OZ-6250-B develops horsepower in the 5000 rpm range, DUAL POINT DISTRIBUTOR COAZ-12127-L is recommended to get the last ounce of performance from your Impressor Kit. This is a 427 mechanical advance distributor (no vacuum advance). So, plug the vacuum line from the manifold. For maximum performance, adjust the stock 6° initial advance to 10° Do not exceed 38° total advance. Install Autolite BF-32 plugs.
SOLID STEEL CORE CABLE
Maximum voltage can be delivered to the spark plugs by installing SOLID STEEL CORE CABLE C5AZ-12259-C. This kit contains cable for 8 spark plugs and the high tension wire from the coil to distributor. Since this "cable" wiring doesn't contain special resistance materials to control radio interference, RADIO SUPPRESSION KIT C4AZ-18827-A is recommended for "street" use.