Just trying to start a debate, really. I have heard many people whine about their L03 not being able to perform, so they just get rid of it and swap a 350 w/carb in. I personally like the L03 for what it is- a very efficient and reliable, torquey little bastard. Sure it's not a 350, and it doesn't have the best parts in it... but I think it's highly feesable to build it up.

Vortec Heads: $300
Edelbrock RPM Air Gap: $175
Holley 670cfm TBI: $175
Adapter plate: $40
LT4 Cam and springs: $150
PROM burning: $75
Gaskets $100

result? ~300hp.

I'll let you know this coming week, as I start my project FRIDAY.

 

It is not pointless but people give up because the mods that they do don't go as far as they would on a 350. Plus being TBI, people assume it is a bad performer and can't make power. Well people usually bash it because they don't understand it. The biggest problem is peopls inability to want to burn their own chips. Sure head and cam and exhaust are all nice but when it runs likes poo because of the stock tune they run for the hills and blame it on TBI. The stuff you listed is only a base of what you need. These cars have a lot of weak links and once you start to mod it you are constantly chanings something else to support what you just bolted on. After you get so much power you run out of fuel, so you get a new fule pump then run out of air. Then you get a larger TBI unit and then you have to tune and you have a one wheel peel. See where I am getting at.

 

ive done many mods. to my lo3, and continue to try new things. im happy with it.

 

Me too, i am happy with my 305, i know its not the fastest thing in the world but, i work on it a little at a time, its fun to see your progress and im gonna love the day when ill be able to take a 350.

 

Well whats an l05 have, 210hp, doesn't take much to beat one

 

A lot of people view the LO3 and TBI as being synonymous that's why it gets a bad rap but if you have vortec heads, LT4 cam and all that stuff you listed its no longer an LO3 its just a modded 305 TBI. I'd take all those parts and put them on a 350 block then you'll have a real nice setup. Just make sure you know how to tune in your TBI then you can get good power and good gas mileage. I say make TBI work don't step back in time and throw a carb on there which ends up costing more money in the end anyways and you'll most likely lose gas mileage.

 

It's for that reason I really didn't want to bother moding mine. . granted it's got no real power for what it is.. compaired to whats out on the road today.. but it's a thirdgen .. it's looks an performs the way it was ment to and that answers it all for me. But I agree too.. having that "extra power" is a nice thing to have.. Though I'd just sooner build a nice 350 on the side..
In the meen time the 305 runs well, gets me where I want to go in style and reasonable power. with decent gas milage..

 

1.) Will a Edelbrock RPM Air Gap manifold line up with Vortec heads?

2.) Will a combo of Edelbrock RPM Air Gap + Adpater plate + Holley 670 + Air Filter fit under a stock hood? I would think that would be too big, so you might wanted to throw in $400 for a new hood.

I don't know really, I'm just thinking out loud. . .

 

You can make yourself a cowl hood with some sheetmetal and a welder
Ive actually seen it done on a subaru, and suprisingly it didn't look to bad.

 

1: yes
2: probably not, but I hear I can cut the bracing of the hood

 

This is a very hotly debated subject on this board.

remeber from the factory, this was the base engine, it is detuned. with just chip work, my car runs as well or faster than many of the 305 TPI cars that i race with.

i put a cam in this weekend, just for the heck of it, since i had it laying around, i changed nothing else, and it really woke things up, i will be going to the track when it opens up here in a few weeks to do some tuning, i suspect mid-low 14's on the stock heads/intake. TBI can make power, but there is so much more to it than just tossing parts at it. take the time to really think about how all the parts are going to interact. custom tuning is a MUST IMHO. the changes in the chip that needed to be made to my car after i put the headers on would amaze people. as much as people want to beleive otherwise, any change needs computer changes to match, headers alone changed parts of my VE table by 15%, that is a pretty radical fueling change, other places in the table, i had to take out 5%-8%, so it is not just a matter of cranking up the fuel pressure to match. in the process of getting it tuned, not only did i go faster, but my gas milage went UP while cruising. once you start to dig into it, you can see how the timing tables, and other peices of the chip, really hold the LO3 back.

 

Well I'm going the 350 TBI route with my Camaro, but with my future Caprice, I'm going to go either the 305 route or a 350 TPI for sh*ts and giggles, it really all depends on my money situation and the condition of the motor.

If the motor is in good condition, then I'm definately keeping the 305, but if not see ya later. I think it would be sweet to get the LO3 to 350 HP, but if I can't do that w/o keeping my drivablity, then it won't fly. I'll let somebody show me the way on here, before I go exploring for it on my own, because I'm hardly qualified to experiment like that.

 

Shifty is right. When you start to tear the car apart and build the engine you'll find all your other weak links. Your stock fuel pump is useless, figure $105 for a walbro. Your rear suspension is usless. I have LCAs, PHR, relocation brackets so there's $300, plus a posi/disc/3.42 rear end which was $310. Then I needed new brake lines in the back, that was $25. Subframes were $150 plus $75 for installiation since I can not weld. Im not tryin to discourage you, but building a car to go fast the right way is a lot more than building a motor. I did exactly what you did after my freshman year in college (heads, cam, intake, exhaust) and now the car will finally be to the point where I'd consider it almost done after my Junior year.

 

Let us know how ya run.

 

IMO the 305TBI is very workable motor for power and speed. The only reason I dropped the 350 in my car was because the 305 was starting to smoke full time and the oil pressure was barely there. The 350 was a freebee from a wrecked truck at the company I work for. I still have all intentions of rebuilding the 305 and finding another third gen to drop it into, TBI and all. As the others have said, once you get beyond the weak spots of the motor the rest is in the tuning and non motor related areas that wil suffer from the added power.

 

For those bashing the 305, don't forget that it'sstill over 300 cubic inches, meaning there is potential. 305's got saddled with the most awful V8 heads GM ever produced, and a cam that barely even has lobes. Also, the stock throttle body is fairly small, and the intake is quite restrictive. Throw in the fact that Mustangs with three fewer cubic inches were kicking their asses, and you have a recipe for a hated motor.

I've been toying with the idea of throwing a few parts at mine, since,you know, the engines already in there and over 300 inches. If I do this, I'll be shooting at probably 270-290 rwhp, or 330 off the crank. I think it's doable.

 

That's a good aspect on why we take so much crap.

 

The way i look at it, people spend a lot of money to make a 305 have around 250-275 hp and run in the low 14's-mid 13's.
For the same money, u can make a 350 run in the 12's and 375-up hp. For $1500 more , u can run a 383 stroker and make some real times.
I dont think the tbi is all that bad, however, I think the chevy 305 is a pretty bad motor to spend a lot of money on.

 

I agree that it's a bad motor to spend a LOT of money on. But it's not a bad motor to spend a few bucks on and have a fun daily driver. The average mongoloid is aware that a 350 is worlds easier to make fast, but it's not unreasonable for those that lack time, space, and patience for a swap to hang a few decent parts on their 305. Wasn't it Chevy High Perf that got 326hp from a 180k mile 305 with pretty basic stuff? That's not bad, and translates to at least 250 off the wheels; right in line with most stock/bolt-on LT1's.

 

it depends on your goals.

if you only want a lil more umph to scoot around, go ahead and mod the L03 and be happy.

if you want to run 11second timeslips dont bother spending money on the 305 that you're going to toss.


alot of people here would be happy with a mildly modded 305..... while others would call it insanly slow and go nuts having to drive that around.

about the only debate and such that comes up is when some guy wants to go fast, but keep the L03.... uuh, great, but you need new heads, cam, intake, exhaust, TBI mods, ect... and when you're all done, and realize that its still not as fast, none of that stuff is the best for your 350.... the small heads that work on the 305, arnt as great on the 350... the cam profile will be a lil too small, ect... so you start over AGAIN.

but anyhoo, no need to bring that argument up again.

the only mods my L03 now has is headers, catback, singleplane intake, and a open element...... total i spent about $50..... i already had the headers, and intake from my old 82... and the open element was a extra from a friend.. only money spent was gaskets, the carb adapter, and $40 for a used catback from a friend.
i currently consider it insanly slow. and it drives me nuts.... part of that is probly that i hate autos... i have a T56 in the garage that is going behind the L03 either this weekend or the next....

sitting on the garage floor under the shelf that the T56 is on, is a 400SBC... i have the 400, some dart heads, solid roller setup, and some other stuff..... im waiting until the drivetrain is bulletproofed with the T56, driveshaft, and 9" (since this is a daily driver)
then the multiport FI, blown 400 is going in.... the idea being that i fix the weak points before it goes in, so i dont break them.
thats the idea atleast.......... if i didnt want to drive it everyday ( i do have a 2nd car, but i dont like driving it) then i could just dump the 400 in now..... but im getting off totally subject..... you start me thinking about my car, and i'll talk for hours.
:lala:

 

we all do that, heck i get started on my car, and i start doing that to non-car people doesn't do well when i talk about my cam shaft for 2hours on a first date

 

Depends on what shaft you are talking about I try to keep the camaro talk to a minimal with my girl. I just refer to it as the "camaro" and thats it.

 

i try not to, but somehow something comes up, and gets me started.

 

Dewey316, i hear you talking about chip burning all the time, that must give you some pretty good results. What kind of results have you seen from that? What times are you running? Chip burniing is something i want to get into, What all would i need to start burning chip and how much will it cost me?

 

bone stock with chip tuning i ran 15.5@90mph

that is down from 17.1@84 earlier in the year with the stock chip.

i WOULD have had dyno numbers, but had some pretty serious mechanical issues on the dyno, and put down a monsterous 136hp, with a 15.7 AFR and firing on 7cyls.

 

Wow thats pretty impressive,so what all would i need to start burning my own chips?

 

Check out the DIY PROM board. Try a search in there and get ready to read your eyeballs out. it is very interesting and easy once you actually get the stuff and start to play.

 

That's the understatement of the year. I got burned out and have now resorted to begging

 

dont dispair...

my advice is to read what you need to get... STOP, buy the stuff...

then mess with it and read what you have to know as you go along.......


its sooooo much easier that way... if you try to learn it all first, instead of getting it and playing with it, you just cant absorb all the info at once.

 

LOL, Freudian slip?

RBob.

 

Here is a good starting article that lists equipment and such. Can be a little confusing as it covers multiple ECMs, just need to remember that the TBI ECM is a C3 ('8746).

https://www.thirdgen.org/newdesign/tech/promintro.shtml

RBob.

 

LO3's fast with not a lot of money spent? Depends on your definition of fast. My recommendation is to build around the motor. Bolt on exhaust, ignition, suspension, rear end etc. and just leave the motor alone other than maybe porting and polishing the throttle body and maybe tossing an intake and rockers on. Once you're done with that and FULLY TUNED, then decide how much further you want to take it. If I would have done it again, I just would have gone this route:

Headers
3" Cutout Before cat
Rear End
LCA's and relocators
Some ignition stuff
Open Element
Nitrous
Lots of Prom Burning
TB port and polish
Extra Set of Wheels with Drag Radials or slicks on em'

After this, I'd rip the thing out and toss in an MPFI 406 and I could even E-bay the throttle body . That combo should be good for some nice times and is fairly cheap. The thing is is that no-one really includes actual prices when they quote these things. There are so many stupid hidden costs, not so much with the mods listed above, but like Intake for example, you're gonna need gaskets, RTV, more gaskets, fasteners, new sensors maybe and all this crap pops up, so some mods may be cheaper to start off with (like the LT1 Cam for $40) but they end up costing a lot in the end.

Just something to keep in mind

 

I couldn't have said this better. Many first time modder over look this in a serious way. I spent $40 for my LT1 cam and spent over $100 in other stuff to make it work. It would have been more but I reused the stock timing chain and springs because of the low miles, B-body LT1 specs (smaller than f-bod), and the fact that this car is not driven and I did the swap as a learning experience. You keep your cost estimates closer based on if you have every tool under the sun and every other gadget (grinders, welders, etc etc) that can help you get a job done for less.

 

ShiftyCapone told me that I should probably get a new timing chain. And I forgot about RTV so I need some of that. There are probably miscellaneous bolts I will lose as well.

 

He is refering to a cam swap.

 

The way I will do it:
Get suspension and drivetrain done first. As you upgrade your suspension you can do some minor mods on the engine like full exhaust, cai, open element, ultimate TBI. Just remeber, at the moment other than engine related areas are priorities.
But when the suspension and drivetrain are ready get the engine done. That way you can every now and then have some extra HP and you don't get bored.

 

This is the smart way of going about things. That way you are safe with plenty of traction when the power does arive. The rpoblem with the 305 is that it is so slow that you get fed up and go for the power adders right away. That's how I was with my Lo3. Now that I have an LT1 I have to do suspension first. I am comfterble with the power and can contain myself for the time being. I can't keep the thing on the road enough as it is.

 

I just wanna know where you can get the Holley 670 for under 200 bucks. Last I checked it was getting closer to 400. Just remember whenever you are modding your engine, L03's are crap, TBI isn't. Anything you do to make it anything other than an L03 will make it better.....(within reason of course)

 

They come up used all the time at that price. Just saw one today on this board.

 

http://search.ebay.com/search/search...0&BasicSearch=

 

lol, doing that right now...

everythings almost done now.... i just have to put the T56 in, and possibly get a new driveshaft (and a DS loop)

after that, its time to finish the 400... all i need is harness, ECM, injectors and cam. weeeeeeee...

 

All I need is new springs, shocks, struts, bushings, LCA's, PHR, rear end, tranny and brakes. After that it is time to "Project 305 Super Beast"