I won’t argue that your driving experience will be enhanced if you can increase the power output. After all, faster is always better, right? A rating of 130 horsepower can be downright depressing. I’ve driven go-carts with more horsepower than that. However, horsepower ratings can be very misleading. Were you aware of the fact that the same engines that were in many classic cars were rated at a much more respectable amount horsepower in 1970 or 1971 as opposed to 1972 and beyond? What happened to the engine that would make it drop (in some cases) 70 horsepower in one year?
The short answer is… nothing. The only thing that changed is the way that the horsepower was measured.
Up until 1971 “gross horsepower” was measured on a bare engine with no accessories attached, optimal ignition timing, and exhaust headers. Beginning in 1972 “net horsepower” was measured with every imaginable accessory attached (air-conditioning, power steering, alternator, water pump, emission control devices, etc.), standard ignition timing, and a full exhaust with mufflers. This new method of measuring resulted in a loss of 70 horsepower although the real output was virtually unchanged. Contrary to popular belief, “net horsepower” is not measured at the rear wheels.
One of the best examples of this is the 500 CID Cadillac Eldorado engine that went from a reported output of 360 horsepower in 1971 to 235 horsepower in 1972 with virtually no change in the engine. Any other minor additional loss in horsepower after 1972 was due to the addition of emissions controls and a reduction in the engine's compression ratio.
To increase your engine from 130 to 250 horsepower on a “limited budget” and in a “do it yourself” manner is virtually impossible. At least not without shortening it’s lifespan to one or two flips of the nitrous switch. To increase it about 30 or 40 horsepower is possible, but both a “limited budget”, and “do it yourself” are relative terms. For less than $1000 in parts you can buy a small 4 barrel carburetor, a matching intake manifold, and a mild performance camshaft. Add another $400.00 or so for a dual exhaust and you should be able to gain close to 40 horsepower from the engine. While not a massive gain, you will definitely be able to feel it when you step on the “go pedal.” If you have to pay a mechanic for the installation of these parts, figure another $1000 in labor costs. This may seem like a lot of money for a few extra ponies, but this tried and true combination is the most bang for your buck.