It all depends on what you consider cheap. My 472 is off at the machine shop atm.
First, if your heads haven't been redone for unleaded gas, get it done.
Edelbrock makes an intake for your engine that sells for $255 at
www.jegs.com. I got mine from ebay for $180.01.
Edelbrock also makes a cam and lifter package matched to that intake. If you have ever seen a 472 cam, you'd understand. It's worthless.
You can get block hugger headers for it. DO NOT buy the ones being sold on ebay by SSAutochrome. I bought a set, and they look like ass. One was so warped that I had to bolt it to a jig an heat it to straighten it.
Lose the Y-pipe and go with dual exhaust with a crossover tube.
I'm running 4" stainless Supertrapp mufflers on mine. They are loud, but very tunable. If you want to mellow it out, put a glass pack right at the end of your head pipe, then the crossover pipe, then the supertrapps. It will give it a deeper tone. You will only get the Ferrari sound when you stand on it.
The Holley analog fuel injection kits are going for 700ish on ebay atm, which is about half price. The digital version is out, so people are less interested in the older analog control.
Here's a really cheap one. Pull your points distributor. Throw it in the trash. Buy a HEI/vaccume advance distributor off a 70's model. Points suck.
A roller timing chain will save you a couple HP.
Btw, I'm doing all of these things, and it's going into an 87 Fiero GT on a THM325-4L trans from an 85 eldorado. Really easy do do actually, if you can weld. The Fiero's engine rides on a subframe that drops out the bottom. This engine is a bit too wide, so i will have to use coilover struts, and modify my strut towers.