I have a stone stock 1985 Trans Am, 305, Q-jet, BW T-5. The car was given to me free, and as you can imagine, it wasn't real pretty, and barely ran. Over the last few months, I've basically replaced the entire interior, and it's starting to look pretty good. Replaced the center link, front rotors, bearings and pads. About all I've done to the engine is new oil pump, new spark plugs, valve cover and oil pan gaskets, and a new transmission mount. Also replaced the radiator, but that was probably a mistake, and will probably switch back to the original in the next few days. Also a new air dam. Ripped off all the old plastic vacuum lines that were broken and misrouted, and replaced with all new rubber lines.
The car now runs excellent, and gets 23 1/2 mpg. The speedo only goes to 85, but is easily buried, 'til the needle hits the mileage reset. Mileage is important to me, as I do a 100 mile round trip every day.
I toyed with the idea of swapping out the motor with a TPI 350, but would rather avoid the hassle and expense.
Somewhere on these boards, I read a thread that dealt with 305 performance improvements. I can't find that thread now, but from memory, it mostly concerned opening up the exhaust and letting the engine reach it's potential. I am looking for the most bang for my buck, and would rather not go into internal engine mods at this point, this is my only ride to work, and max downtime has to be limited to a weekend.

So, here's the questions! What are the best headers I can put on here (brand name, price, source). Does this require a new Y-pipe, and if so, brand, price, source? Is a true dual exhaust a better option? (brand, price, source) What about catalytic converters and mufflers? What the heck is a cat back system?

 

P.S. - Where I live now, I don't have to do smog inspections, but I'm moving soon, and that may change.

 

well nobody makes true duals for our cars, that would have to be custom which would be expensive, but a good muffler shop could do it, but you would end up with ground clearance issues. for headers, hookers are good, i think the 2010's w new y-pipe would be good to match the pipe diameter, and the catalytic converter would be a good idea to replace, magnaflow direct fits are pretty good, the cat-back is just that, the exhaust system form the catalytic converter back, if you didn't want to spend too much money you could just replace the converter and then do a cat-back exhaust, i like the flowmaster american thunder kit for a catback which is around $400 on summit, there is a borla kit too but that's around $800 on hawks thirdgen parts, or a chambered exhaust catback system also for around$800.

 

Well, I was just browsing Summit's site, and this is what I came up with:

Hooker 2460 shorty headers at $154.95
Hooker 16767 Y pipe at $203.39
Hooker 16820 cat back kit at $285.95 (this includes a new Hooker muffler)

This looks like it will all bolt right together, but not much is mentioned about the catalytic converter, will this all work with a stock cat?

The Y pipe has no provision for an oxygen sensor, what do you do about this? Leave it off? Weld a boss and drill it and tap it?

For a total price of $645, plus probably an ungodly amount for shipping, will I have an appreciable performance difference?

 

the oxygen sensor on the stock manifold is on the driver side right a the end where the y-pipe bolts to the flange. you could reuse your old converter but i would highly recommend a high flow cat, the original will jsut work against your goal. a full exhaust will usually add 10-15 more hp

 

I don't have it up in the air right now, but I could have sworn the oxy sensor was on the right side of the Y pipe?
Looking at your previous post, does the Magnaflow direct fit cat have a provision for the air injection pipe?

 

The 2460's have an O2 bung in the stock location.Sounds like a good set up....I'd check around as you can find the 2460's used for less than $50.
Good luck,
Mike