I have a 91 L03 with 110K miles on it. Doesn't leak a drop of oil or use any. 3k miles and will still show full. So I can't justify to the wife dropping $3500 in putting a nice 350 crate motor in there including new throttle body and you get the picture. 170hp sucks. My wife runs off from me in her 98 190hp Maxima. I mean its not even close. Since it is a late model block and should have provisions for the roller lifter setup inside. Can I put maybe a used 90 Vette roller cam in there with some valve springs maybe 1.6 roller tip rockers. Change to headers with 3" exhaust and get this thing up to maybe 220hp(at the engine not the rear wheels). 220hp at the rear wheels is a hell of a lot more than what it has now so I am looking for a 50hp gain. Is that too lofty a goal without swaping the heads and probably blowing out the rings. I would like some decent performance until I come with the money and an excuse to pull the motor. I don't want to go too radical on the cam either. I want it be more like the stock L03 should have come new. I am already working on the aircleaner breathing. Any other suggestions would be appreciated.

------------------
91 Camaro RS 5.0L Black Convertible 700R4. Owned 5 months bought from 1 owner girl. Working on that stock part.
** Added so far **
*GM Wonderbar
*Alston SFC

 

Exhaust first, all the way from the heads to the bumper. It won't make a big difference by itself but is required for anything else.

Then the cam. You have the most pitiful cam ever to humiliate a small block Chevy. Get it out of there, and get something like the Comp 260HR.

Those 2 things by themselves are the better part of 50 HP.

Get a dual snorkel air cleaner from a L69 car, it is good for probably 5 HP over an open element due to picking up cold air instead of hot underhood air.

------------------
"So many Mustangs, so little time..."
ICON Motorsports

 

Harris,
You are right in wanting to increase the breathing of the motor first. A free-flowing cat-back with a quality muffler (I personally prefer Flowmaster, but Borla, & Hooker also offer great pieces), and headers if they are in budget, are a good starting point. As you mentioned, you need to get air into the motor too, so a K&N filter will help. You could make a ram-air setup to maximize your potential. One piece you didn't mention is an aftermarket PROM. This will help to make the most of your current set-up, and becomes a "must" the further you go.
Unfortunately, while this provides a solid foundation to build on, it will not give you the extra 50hp you are looking for. A good cam choice will put you close, but you could also look at other areas of the car. Examples: B&M or Trans-Go shift kit for the 700R4, 3.73 or higher rear gears, etc.

------------------
'87 IROC Z28
TPI 305
5-speed w/ Centerforce clutch
3 1/2" exhaust w/ Flowmaster
Clarion, Kenwood, Eclipse, Polk, MTX, Autotek 800 watt stereo system
Grant wheel
Otherwise stock, & good for a 14.68 at DeSoto Dragstrip
More to come soon...
Shooting for high 13's with bolt-on's

 

On the cam what about a stock 4th gen LT1 roller. Or a 90+ Vette cam. Maybe a 300hp Vortec crate cam. I can find these used with the roller lifters (since I believe my L03 should have flat tappets but provisions for the roller hardware,please correct me if I am wrong). The used with the roller lifter stuff is at least half the price of just a new roller cam and roller lifters aren't cheap. I good stock 350 roller cam I would think would do wonders for a smaller 305ci engine. It wouldn't swing my powerband over tooo much either. What ya think? I know roller cams wear much better than flat tappets. I wouldn't even consider using a used flat tappet cam. Suggestions? I would rather spend some money on the exhaust which I can use for a while (lifetime really down here in the south). Than spend it on a cam for an engine that I might get 2 more years from.


------------------
91 Camaro RS 5.0L Black Convertible 700R4. Owned 5 months bought from 1 owner girl. Working on that stock part.
** Added so far **
*GM Wonderbar
*Alston SFC

 

Exhaust is a must before anything else. At least a complete 3" system with H.O manifolds, but headers are better.

An open element air filter, or dual snorkel is also a must since the stock one would barely support a 4 cylinder.

Bump you timing to 6 degrees BTDC and run 93 octane.

Just these mods alone brought the E.T from 16.5 to 15.6 seconds on my brother's 92' RS.

A set of 3.42 gears would help too since the stock 2.73's hurt performance. The 2.73's will begin to be a bigger problem if you put a bigger cam in which will raise your torque peak. They can be addressed at a later time though.

You do have roller lifters. So you can re-use the old lifters as long as they are in good shape. As for cams, an L98 cam may be good if you can get it cheap, also, Scoggin Dickey has take off ZZ4 cams for $100. It might be a little more wild than you would like, but anything in between those would work well.

The only problem with a cam is that you will have to get a new chip burned for that cam since the computer uses a map sensor and the readings will be very different, and the fuel maps will have to be changed.

A larger throttle body would be the next step after a cam, then heads.

This should keep you busy and net some marked improvements in performance.



------------------
89 Transam GTA, 350TPI, auto, 3.27 rear, dual cats, gray.
Magnaflow cat-back,
K&N open element,
Best E.T. 14.63@95mph

 

Looks like exhaust is my next project. Thanks guys. I will make a post in the exhaust section to get some advice on that. I will look at the ZZ4 take out cam. Good price. I just didn't think the L03 had roller lifters since my 92 Truck 350 didn't.


------------------
91 Camaro RS 5.0L Black Convertible 700R4. Owned 5 months bought from 1 owner girl. Working on that stock part.
** Added so far **
*GM Wonderbar
*Alston SFC

 

Sorry, I'm not adding any info to the topic, but brharris, how are you working on the aircleaner breathing? I Have the same problem as you. I'm trying to get the most out of my 305 TBI as I can without a new engine. Except I'm going for the best gas mileage and power I can get at the same time. If any of your mods get you those results, I would appriciate your info. Once again, sorry for the offtrack subject.

 

My new air cleaner mod. I took the old air filter from my 92 truck. Swapped the lid and filter which is about an in taller than stock. Fit under the hood without any mods. I also cut the snorkel off of the truck air filter and welded it to the front of my camaro air filter. That way I can at least pull air from in front of the motor and if I can find some hose I would like to plumb it over to the battery area for some colder air.

<img border="0" src="http://www.bharris.org/images/camaroair.jpg" width="1024" height="768"></p>

------------------
91 Camaro RS 5.0L Black Convertible 700R4. Owned 5 months bought from 1 owner girl. Working on that stock part.
** Added so far **
*GM Wonderbar
*Alston SFC