FAQ - Aluminum rods
The advantages of aluminum rods are as follows:
Lighter weight. Means less stress on the crank, (longevity is increased) and allows the engine to wind up to its potential, and more importantly - quicker. Thus improving e.t.'s.
Also we can make more efficient rod length designs. We can make the big end and the pin end smaller in diameter. You cannot make as big as change with any steel aftermarket rod for the price.
Aluminum rods do not stretch to a worrysome amount in a Pontiac. Our pistons are lighter and that makes a big difference.
They will not break. They can be run on the street with no problems.
The only extra consideration you give to them is upon fire up.
You simply let the engine warm up to at least 140 degrees before
you whack the throttle.
If you live in a very cold climate, you would make sure that the ambient temperature is at least 50 degrees before starting the engine. Use an Accu-sump pre-oiling system before fire up. They're only $245 and every car should have one anyway. If you're going to do heavy road racing, with lots of on-and-off the throttle, you would probably want to go to a steel rod. Other than that, they are always an advantage.
Last item. Always run a light weight piston and pin with an aluminum rod. Never run a TRW style forged piston and expect the same kind of life from them. How long do they last? Don't know exactly. I've never seen one break on it's own. Failure has always been caused by another event. I know one guy who has over 500 runs on his and is still going strong. Run .0020 bearing clearance on the street, and never more than .003 on a 7500 rpm engine.