Chevy Nova: Put That Rat on Steroids
Ron Shagool; Bardstown, KY: I am in the process of restoring the first car I ever owned—a 1970 Chevy Nova that I was lucky enough to hunt down and purchase. As with most people in this economy, I am trying to stretch every dollar. Over the years I have been able to collect/accumulate a number of big-block Chevy engines, and feel I should use what I have on hand to save some money. Most of these are 396ci engines.
I found a website that specializes in stroker kits and located one kit that claims to increase a 396ci motor to 434 ci. It comes with a 4.00-inch nodular iron crank, forged rods, and hypereutectic pistons for $1,350 or $2,200 for a steel crank and forged pistons. Do you know much about these motors after such a stroker kit is installed?
My second question concerns the factory 049- and 781-casting-number, cast-iron, oval-port big-block Chevy Nova heads. I know many articles have been written about the good flow numbers of these heads and engines that have been built utilizing them. But I have never heard of anyone building a 396-based engine using these heads. Most people use the closed-chamber 396 heads that came out on these motors (215, 290 casting numbers). I would rather use a set of the open-chamber 454 heads for my Chevy Nova (I have both 049 and 781 castings). I have been told I must be careful with not putting too large a valve in the heads and using them on a 396 motor due to the smaller bore versus using them on a 427 or 454 motor. Is this true? I have also been told that the 049 would be the better head for a 396 and the 781 head would be better on a 427 or 454 motor. Is this true, or are there any differences at all in the two castings?
When the motor is finished, my Chevy Nova will be used for street cruising and the occasional trip down the dragstrip. I would like to build a motor using as many of the factory parts as possible but upgrade them with some of the later technology, such as a hydraulic roller cam, roller rockers, an aluminum intake, headers, and so on. Should I even pursue these heads, or should I just order new ones? I have seen Patriot aluminum big-block heads advertised for $1,350 to $1,400. I have no predetermined horsepower figures I have to meet or rules I have to live with to race in a particular class. I have already built a 200-4R overdrive transmission and currently am rebuilding the 12-bolt.