I drive a 89 cam with a 305 TBI, i'm wanting to go 350 carb but curious about what i should do when i buy a 350 carb and get as bang for my buck for power (budget = 500 after buying engine) before i install it and still have it pass emissions. Any tips or past experience would be greatly apprecaited. I live in Connecticut so i believe its 25 years till emissions doesn't matter anymore here, so i'm wondering what I could do to get around it if possible?

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Timinsk

 

You'll never get any carburetor to pass emissions, you must keep your car fuel injected. This isn't a bad thing, it's actually got more advantages than disadvantages.

 

If your car originally had a throttle body fuel injection system on it, you can't put a carb on it. All you need to convert to a 350 is a chip and two new fuel injectors from any car/truck that had a TBI 350. If you have a good working smog pump and CAT you might pass the sniffer. But externally they are identical.

 

really carb wont pass at all? tbi has no power and no one in ct can tune... i feel like im wasting money for nothing.. carb is like instant power.. idk wht to do :\ feels like it'll be ages till i can get anywhere...

 

Is your SES light coming on? If so, retrieve the codes and fix what's causing it.

Tuning a 305 TBI is a matter of replacing spark plugs, spark plug wires, cap, rotor, O2 sensor, air & fuel filter, and setting the timing. As long as the engine hasn't been severely neglected, those things will bring it back to where it should be. You may need to replace the ignition module and coil, but those things usually cause problems other than "no power".

If by "no power" you mean 170 HP = zero power, then that's a different story - but still doesn't have anything to do with someone being able to "tune" it.

 

all i keep being told is that i could swap cam and have either new heads with bigger chambers and also the exhaust done to be 1 5/8 to 3" and along with maybe bigger tbi unit sizing about 2" each and a bigger intake and it might not run properly because it needs to be "tuned". yes sorry i mean hp and tq, i tuned it all up for spark plugs, etc.

 

With proper mods, TBI can support well past 300 hp, it's not your problem. The LO3 it's sitting on top of is the problem. Tiny cam, no-flowing swirl-port heads, restrictive exhaust system, restrictive air cleaner, even a crappy intake manifold. That's why you have only 170 hp, NOT the TBI. And since NO '89 GM V8 car was built with a carb, a carb cannot be legal in your '89.

 

i know.. but what could i do then? or could i swap to 350 tbi and do something with a l05?

 

If you put good matched heads/intake/camshaft and a high flow throttlebody/exhaust/aircleaner/headers with a properly tuned chip by a competant tuner I can garauntee you can make that little thing run good. Passing the sniffer may be difficult with all these mods but a 305 on TBI can be made to run decent.

I had a 92 camaro with a TBI 305 with all these mods and it ran like a completely different animal. I later replaced it with a 11:1 327 and it still ran well with a good chip.

 

doing a TBI 350 is the right idea, but not using LO5 heads. GM has an intake manifold, made for them by Edelbrock, that'll let you put your TBI on Vortec heads. That's a much better idea.

 

wait, better yet, use Edelbrock's E-Tec 170 heads, that'll save about 50 pounds off the nose of your car.

 

A 350 TBI buildup will make more power and be cheaper/more reliable than a built 305 in the long run. If I was going to go thru the hassle of an engine swap It would be a 383. But if you can't afford a stroker a 350 with good heads/cam/intake/high flow exhaust/high flow throttle body/ and a good chip will run very well. And remember EFI is a little more difficult up front, but once its setup up correctly it will provide a smoother idle and trouble free performance for a long time. You will most likely not pass emissions with a 350 though.

 

really i wouldn't pass emissions with a 350 tbi? what could i do for now with whats available at my disposal to get around the sniffer but gain more hp from my 305 and then later go 350 tbi and maybe any list of parts from jegs or something might help like links to what i could look to get. I heard on a stock 305 tbi a bigger exhaust would lead to no back pressure. I'm looking a the 1 5/8 to 3" all out.
this is whats done to my 305 tbi right now:

- tbi spacer
- msd ignition coil
- msd dis cap
- gapped spark plugs about .03 more than stock i believe
- new spark plug wires
- open air element 14x3
- k&n filter
- a/c delete pulley
- hypertech 305tbi chip
- ultimate tbi mod


only problem i have is the blue puff of smoke when i start my car everyday but runs clean after that. i think its normal since i believe the valve stems shrink and let in oil then expand when heated and soot releases... from what i believe.. but other than that i think things are good.. but thats all i have done to it, really not much to say its a big improvement.

 

If you build it as bad as possible, it probably won't pass emissions.

If you keep everything emissions- and computer friendly, it shouldn't have any trouble passing emissions.

 

thats what i thought so if i follow by what should be done to properly setup a smooth running 350 tbi with cam, heads, intake and exhaust done it should pass emissions fine?

 

The B-body cars (Caprice, etc.) had TBI 350's, and had to meet the same emissions requirements. Of course they weren't "performance oriented", but it is possible to make a factory set-up more "performance oriented" and still pass emissions. The keys are keeping all of the emissions equipment intact and functioning, and picking a cam that is emissions-friendly.

 

i guess i'll hold off on doing the swap because i truly want to get rid of the emissions equipment, save up room and less problems if they do fail later...

 

In that case, you better do an LSx swap. They can be legal with almost nothing obvious fuglying the engine bay. That, or move to a town where they don't do emissions checks.

 

darn lol, lsx are expensive from what i see....

 

oh yeah, killer expensive. I picked up my second truck 5.3L LSx for $75 complete from Pick-N-Pull on half price day. My first one was $500 from www.lkqcorp.com, also complete. You can find the camaro oilpans used on www.ls1tech.com for like $25, same for the intake manifold. The one big expense is the $700 headers.

 

Yeah down at the junkyard i used to work at you could pick up a 6.0L truck motor and trans for under 2000 easy.

 

my god... i wish i made that kind of money.... no luck in my budget for that anytime soon sadly.. what could i do for now?

 

let the 350 or LSx wait until you've saved more money. Or you could install nitrous on your 305. That'll be $500.

 

rather have $500 worth of internal work and run safe rather knowing a rod will shoot out of my hood at about 5500 rpm and just hear a big 10 buck shot go off in my rear...

 

I know from firsthand experience that your LO3 will take a 100-horse shot of nitrous, and I know from experience that a stock, high mileage LO3 is fine to 6200 rpm.