Early Chevy Re-PowerOur early Chevys are in a constant state of change. First it's a simple stereo install. Then we move to bigger and better things like electronic ignition, electric fuel pump, electric cooling fans, electronic fuel injection, and aftermarket air conditioning. You can see where this is going; the word electric is in just about every modification. And the power demands we put on the battery and charging systems grow. When our cars were built back in the '60s, they had a killer charging system if they put out 63 amps! Now, a sound system, cooling fans, and electric fuel pump can eat up all of the 63 amps, leaving you in the dark-and on the side of the road.
When the electrical system demands grow, you must think about the system as a circle. First is the ability to keep the battery charged and feed all the power accessories. Next is the gauge of the wiring for the charging side of the system and the power feeds and grounds of all those new power accessories. The early Chevelles and Camaros used a 12-gauge wire from the battery to the horn relay as a junction block. From there the power goes through the firewall plug to a junction in the underdash wiring harness. This is the total load center of the whole car. When the demand goes beyond the load-carrying capability of those wires, heat and resistance comes into play, which can be very dangerous and leave you stranded or, worse yet, on fire.
The aftermarket manufacturers, like Painless Performance, have stepped up with complete wiring harnesses that feature larger fuse panels with additional circuits. Also, the wire gauge is more appropriate to the loads of today's accessories. If your factory harness and fuse block are in good condition, you can use components from sources like M.A.D. Enterprises and build your own electrical upgrades. This can be done circuit by circuit, or you can install power junction blocks using power relays for major load centers. Either method will get you there; just be sure to research the one you are most comfortable with and take care of your wires.
Shoe Box RearQ.I own a '56 Chevy Bel Air with a six-cylinder and a powerglide transmission. I'm considering installing a 350ci engine but am at a loss on what size and horsepower output and transmission to use with the existing original rearend. Thanks for the help.Steve CsajkaHershey, PA
A.Steve, many a Pumpkin has been split behind powerful engines in the early Chevys. The drop-out or pumpkin-type rearend in the '50s Chevys are not the strongest. However, if you are going for a 400hp street cruiser, and don't plan on sticky tires and the dragstrip all the time, it'll live fine. Although with 50 years of service on your rear, you may want to upgrade the axle anyway. Let's take a look at what's out there.
The '55-57 Chevys have a common 59.75-inch-axle flange-to-axle flange dimension with '67-69 Camaros, '68-74 Novas, and '64-67 Chevelles. This makes swapping out your diff for a strong 12-bolt, or late 8.5-inch-ring gear 10-bolt, quite easy. Yes, the Camaro, Chevelle, and Nova 12-bolts are like finding a needle in a haystack. However, you can still pick up '72-75 Nova 10-bolts at the wrecking yards. Swap out the spring perches and set the pinion angle, and down the road you go
Now, if you want to give your '56 some love, look to Moser Engineering. They offer brand-new 12-bolts that are not rebuilt. They have cast up a new nodular-iron housing featuring giant main caps with 1/2-inch capscrews attaching them. They have beefed up the cases in weak areas and come with all-new axle tubes and housing ends. You can purchase the housing bare or completely optioned out to your axle specs, gears, limited-slip or spool, and the spring perches in place for a straight bolt-in. If you went this route, you could bolt it in and forget it. Stick in whichever powerplant you wish and have fun. You can get more information from Moser at (260) 726-6689, or online at www.moserengineering.com.