Concerning a dead-stock '82 quadrajet 305: we just completed swapping in a '91 T5; car has 3.73's, very clean original car. We have a built 350 almost ready to go in--but--now the car is running fine, beats nearly all the kids for a hundred miles in any direction, and gets 29 mpg on the highway. Good grief, why change?
Only two points of dissatisfaction: 1, the idle is buttery smooth and 2, it tops out at 4k rpm. I'd like to get a better idle for sitting at red lights and give it a top end of about 5k rpm.
Cam companies say I can upgrade one level without disturbing the computer--I've never liked computers or smog stuff but now I wonder, is that computer what's giving me the 29 mpg? I'd hate to lose it. If I keep the computer do I need to keep the air injection stuff, too, so it'll get accurate readings, or can I put on a set of headers and dump the air injection?
I'd like to put in a cam with a range of 1500 to 5000 rpm, dump all the smog stuff and add a set of headers--what would this do to my mileage?

 

For the most part, the computer or carb'd cars is pretty "stupid" because you can change that stuff, and the computer doesn't really know any better. You can safely upgrade the cam on a CC carb car without the computer fighting with you about it like a TPI car would. All the computer needs to be happy is the knock sensor and O2 sensor reading right, and both would be fine with a hotter cam (just stay away from solid lifters).

At least, thats the way I've always known it to be.

 

What heads and cam do you have now?

There are headers made that are fully emissions legal, if you need them. SLP for one, makes 1 5/8" primaries with AIR tubes and o2 bung. One of the better Y-pipes I've seen in a while, too.

 

Thanks--seems that computer has just about the level of mental activity I like, O2 sensor for mixture and knock sensor for timing.
I bet I could put in a hotter cam, take off the whole AIR system to clean it up under the hood and run headers with an O2 sensor bung welded in at the Y pipe. The motor is a typical 305, runs great in every way but needs valve seals--102,000 miles--doesn't use a drop of oil, bump starts.
Heads are dead stock as is the cam. If I look down the intakes and see a lot of crud I'll take off the heads, too, and do a mild street port. Otherwise, all that stock stuff is giving me almost 30 mpg on the highway with 3.73's so I'm not encouraged to mess with it. I'll probably just put it all back together with the better cam, new seals and gaskets and run it. I have a Weiand Stealth intake and Holley 600 double pumper sitting on my kitchen table, ready to go on the 350 out in the barn--but I'd have to change the hood, the stock T5 (which is in excellent shape) would need to be beefed and I might have cooling problems.
Any suggestions as to heads? I've found that cleaning up a stock set of heads, just taking out the casting imperfections and smoothing the exhaust side with a mild to mid-range cam does wonders on the steet.