396 Torque MonsterIf you're an avid Chevy High reader, we're sure you'd relish the chance to get a bankroll of $5,500 to build your own small-block to your specs. For this opportunity I decided to build something other than what we've built over the last few years. The target performance range of this motor is something that will easily produce lots of torque and work very well in a street-driven performance car. That meant a completely different displacement, a not-so-often-tried camshaft, and a set of low-cost aluminum cylinder heads. The shop I chose to accomplish this engine build was Larry's Performance in Montebello, California.
For many, the term 396 conjures up thoughts of a stout big-block Chevy, but in this case all 396 ci are stuffed into a four-bolt-main 350 Mouse block. This buildup started with a well-worn '79 Chevrolet small-block casting that had been pulled from a half-ton truck and bored 0.030-inch over to achieve a 4.030-inch cylinder. The large displacement from the 350 motor is achieved by axing the stock 3.48-inch stroke crank and replacing it with a 3.8750-inch forged-steel shaft fitted to a set of 6.00-inch I-beam full-floating rods and SRP forged pistons. Yes, this means a very short 1.062-inch compression height on the pistons.
To support the midrange power goal of this combination, an Isky 292 Mega cam with 505-inch lift, 244 degrees of duration (measured at 0.050-inch lift), and 108-degree lobe center got the nod. The ignition system is a proven MSD unit and MSD ignition wires. Then a set of aluminum cylinder heads to help lighten the load and a Professional Products dual-plane intake topped off the package to provide good engine performance within the budget.
When we had finished we were rewarded with a big 481 lb-ft of torque on the dyno and almost 440 horses. Yes, big power for little money.
| CAMSHAFT SPECIFICATIONS |
| Manufacturer | Isky |
| Part Number | 201292 |
| Type | Hydraulic flat-tappet |
| Valve lift | 0.505/0.505-inch intake/exhaust |
| Duration at 0.050 | 244 degrees /244 degrees |
| | intake/exhaust |
| Lobe center | 108 |
| DYNO DETAILS |
| Headers | 231/44 long tubes |
| Advance | 38 |
| Fuel | 91-octane unleaded |
| ON THE MOTOR |
| Max torque at rpm | 481 at 4,100 |
| Max power at rpm | 439 at 5,400 |
| Average torque | 450 |
| Average power | 386 |
| Nitrous Works Plate | 125-Shot |
| Advance | 31 degrees |
| Max torque at rpm | 663 at 4,400 |
| Max power at rpm | 579 at 5,200 |
| Average torque | 492 |
| Average power | 421 |
396ci Build SheetSpecifications not listed are the same as stock. Except as noted, all dimensions are in inches or fractions thereof. All prices sourced through Larry's Performance.
| Displacement | 396 ci |
| Bore x Stroke | 4.030 x 3.8750 |
| Compression | 11:1 |
| Rod center-to-center | 6.00 |
| Piston deck height | 0.015 |
| Compression height | 1.062 |
| Chamber volume | 64cc |
| Rod-bearing clearance | 0.0020 |
| Crank endplay | 0.0060 |
| Piston-ring endgap | 0.020 top; 0.030, second |
| Main bearing-cap torque | 65 lb-ft (moly-lube) |
| Rod-bolt torque | 50 lb-ft (moly-lube) |
| Head-bolt torque | 65/70 lb-ft (moly-lube) |