If your car or truck has a small-block that's long in the tooth or has seen a hard life, odds are it's not running with the same pep it had when new. You might even be burning some oil and hearing a few funny noises that are cause for concern. But thanks to GM Performance Parts, giving your Chevy an injection of fresh horsepower is easier than ever.
The motor in this '92 Camaro RS was definitely showing signs of fatigue. With almost 210,000 miles on the clock, the 305 still ran OK and wasn't consuming oil, but definitely lacked whatever meager punch it had when new. There was debate about building a fresh 305 for the car, but in the end the decision was to go ahead and replace the 305 with a bigger and more powerful 350. Not to say the 305 is a bad motor, but with the future plans for this car, a 350 made more sense and gave a much higher performance ceiling.
But what 350 to replace it with? That was the question. Do you find a junkyard 350 to rebuild, build a fresh engine from all new parts, or go the crate engine route?
After a call to GM Performance Parts, we decided to put together a fresh engine from new parts. The foundation would be a ZZ4 short-block (PN 12561723), so we looked through the GMPP catalog and picked out the rest of the parts to assemble a long-block for the Camaro. The beautiful thing about this build is the engine could virtually go in any Gen I SBC-equipped car or truck. We went with the GMPP Fast Burn heads, but being a small-block Chevy, the choices are virtually limitless.
Follow along as we put everything together to give this '92 RS some much needed zip.
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GM Performance Partswww.gmperformanceparts.com
When new in '92, the L03 made 170hp with throttle body injection. Its TPI equipped LB9 sibling made 205 horses. The engine ran well, with no smoke, oil consumption, or mystery noises that indicated it was on deaths door. Driving the car back from Atlanta where it was purchased, the 305 chugged out 26 mpg on the highway, running about 70-80 mph Not bad for a 17-year-old engine with a ton of miles. On a Mustang chassis dyno, though, it only sent 126 ponies to the wheels, a definite sign more power was needed.
The foundation for this engine is the stout ZZ4 short-block assembly. It features a forged crankshaft with one-piece rear main seal design, four-bolt mains, powdered metal rods, and high-silicon aluminum pistons with offset pins. The block has both side and front engine mount bosses, making it easily installed in any Chevrolet car or truck. It also features a fully machined mechanical fuel pump boss, so the engine can run either carb or fuel injection.
This short-block is a great start for any engine build, from street performance to moderate racing use. If youre new to engine assembly, dont have all the necessary tools, and your mechanical expertise is limited, play it safe and get a pre-assembled short-block, or have your local machine shop do it for you. It only takes one small mistake in short-block assembly to spell doom for an engine.
There was some packing grease built up on the short-block, so we wet down a rag with some mineral spirits to clean things up a bit. We also cleaned the tops of the pistons too.