I have an 89' RS, 305 LO3 converted to carb. Not looking to build a 10 second car, looking for a very peppy daily driver using my 68,000 original mile engine, and freshly rebuilt tranny.

H/C/I:

I was thinking of using ported heads off another 305 my friend has laying around, not sure of the specs or bolt pattern.. just know he said they'll work. What do some of you who've made real power from these hated engines think? What kind of heads should I look into getting, and about how much would they be? Are trick flows really as good as they claim?

Cam: Lunati Voo-Doo, something not too radical.. Like a 230+ duration

Intake: Performer RPM air gap

Carb: Using the 600 CFM edlebrock I got on it now..



Estimated power output? Any input on this combo is very welcomed. Thanks everyone!

 

Also, I know that all-motor I won't ever really have more than a low 13 second car, how do these engines hold up to something like a 125 shot?

 

Lunati 60102 would do you well in the regards for an upgraded cam that's mild.

The performer RPM wont' fit well under the hood, but with a drop base air cleaner it's doable. I'd go with a standard Performer as you won't see that much of a dfference between them

For the heads, World Performance sells a set of "Torquer S/R 305 heads which are your stock 305 heads ported, polished with 1.94 intake valves in them. MW66nova on this site runs a set of stock heads with those valves and he had a really nice 300hp 305 until he went LS.

Do you have headers and a 3" catback on the car yet? The intake and heads wont' see much gain without the headers and exhaust. upgraded as well.

For the carb...I like the Qjet, but that's me. if you're happy with the Edelbrock, stick with it.

 

I agree with all of this. I would go with a holley or qjet carb though, edelbrock carbs aren't very good.

 

don't forget about these
http://www.trickflow.com/partdetail....1&autoview=sku

and of course, 113 casting vette l98 heads. they can be good budget heads too.

i 100% believe that the performer rpm will outperform the performer, based on previous experiences looking inside of both, and utilizing both on different combos. i have no comparative numbers to back those claims though.

 

Factory iron heads that can be had cheap, the best are vortecs. you will need a vortec compatible intake.

I would however invest in some of the cheap aluminum heads available on Summit for 305 motors.

 

i have 906 vortecs on the Caprice L69 shortblock in my Camaro, and it works pretty damn well.. it would probably work even better if i hadn't put in the smallest cam i could find because i was chasing mpg's and reliability when i built the motor last year..

 

ZZ4 heads work GREAT on a 305 build. Look at what I made running them and a very EFI friendly, streetable cam.

 

Thanks for the input guys, I called and found a set of vortec heads at a local junk I can get them for 125$, I'm still debating on those or ported heads.

 

you will be WAY money ahead with the vortecs, even though they take a specific intake. no amount of porting on your 187's will out perform the vortecs even stock, and the port job will cost way more than the heads (even milled, and refreshened) and a proper intake.

 

I was talking to a guy today who has a set of ported and polished 041 heads, he was wanting to sell me for 300$. He said the machine work done on them was that alone, he claims they'll bolt right up to the 305 I just have to get different valve covers, what are you guy's thoughts?


I'm pretty much hell bent now on a Lunati cam, with matching lifters and springs, performer RPM intake, I just needs heads haha.

 

why not stay roller cam man? you have a roller block, it'd be stupid to go to hydraulic flat tappet.

 

Please dont go with a flat tappet cam, youre just asking for trouble. You'll be spending twice the money when you shear a lobe off. Also flat tappet lifter wear inwards, meaning the more mileage, the less lift youre getting

 

X3 HYD Roller

 

Theres going to be a riot if you dont go roller

 

AGREED!!

 

Okay, i'm good with a riot as long as you guys don't go 'BUILD A 350 FGT' on me. I'll listen haha

 

Going flat tappet with a roller block is wayyyyyyy worse than everyones "build a 350" crap.

In all seriousness, not only will you see better gains with roller, but you wont have the possibility of wiping a lobe and having to buy another cam and another set of lifters

 

the cam i listed in my pm to you yesterday would be very ideal for your goals man

 

Already searching on jegs for that cam, I got side tracked with a ebay chrome kit.. ughh back on track.

Roller it is.

 

http://www.summitracing.com/parts/cc...make/chevrolet

 

Got it. Hey I was wondering what all is involved with changing the cam in a third gen? I'm so used to working on a full size silverado this is different when the engine bay is so small haha. Just the radiator, etc?

 

and ac condenser if it's still in there

 

Yeah, it's here. Shes all original but smog pump removed.

 

That cam is very similar to the XFI 280 I had in my 423 HP TBI 305 build. The XFI was on a wider 113* LSA and had more intake duration and more lift with its 1.6:1 rockers.

 

I'm looking into that cam with a kit. Did you get a choppy idle out of it?

 

that big of a cam in a 305 is going to chop, no matter what you do.

 

That's kind of what I figured but I still wanted to run my borla that's why I thought I'd ask, muffler was expennsive af haha.. I bet it'll sound wicked. I'm going to go ahead and order that cam, but I need to find a kit for it.. I'm positive that big of a lift I can't use my stock rods and rockers.

 

yeah, hardened pushrods and proper roller rockers are a gimme in this situation.

 

Valve springs?

 

http://www.jegs.com/i/Comp+Cams/249/CL08-423-8/10002/-1


I found this kit, but I was just thinking there would be something cheaper.. And I'd still need rods and rockers. Holy crap..

 

why do you need new lifters?

 

Because you can get a new set of LS7 roller lifters for about $125.00.

 

this is a good idea.. going with comp cams lifters seems like extra money that he doesn't need to spend though.

 

Man, just give me links to everything I'll need for the cam lmao.

 

So, to make aluminum L98 heads work on an 88 305 tbi engine, WHAT is needed?

old style manifold and L98 head gaskets right? Is that it?

 

Pretty much.

 

The only issue I possibly see with going down in that manner is that the larger combustion chamber of the 350 heads will drop his compression down quite a bit costing power/performance.

 

aluminum l98 heads have a 58 cc combustion chamber, won't effect scr at all. he could actually run a 305 head gasket honestly.

 

My build was completed 3 days ago, haha. I learned A LOT from you bro, and Robert Frank/Dokota over PM and followed there advice to a T. I found a set of decent l98 vette heads for 125$ and polished them up and used them. I didn't really have a lot of cash left for the dyno, as in my area it's 65$/hr.. but on the 3 runs we did the average was 328 crank hp using a 600 CFM carb.. I wasn't too disappointed.

In the near future I'm going to actually take everyones advice for once, and go 350.. because I'm getting a 4th gen trans am soon to fulfill my pleasures haha. I'm thinking LT1 or if I have enough for a decent one, an LS1.

It's still nice to know that 24 year old car w/ original 305 can run over a stock LT1.

 

What did you do with the cam?

 

You'll be happy to know I didn't go with a flat tappet lol, after I got everything apart and in front of me intake, heads, etc.. exposed the valley everything was pretty straight forward and I can see why the flat tappet wouldn't work now.

I'm running a comp roller cam, 276 intake, 282 exhaust. I'll post a clip of the car running soon if you guys wanna see it, it's choppy at idle but isn't over whelming.. the sound is 75% decreased by my exhaust system. The dyno run was through longtubes into high flow cats on each side (The flanges bolted right up for some reason.. and was insanely loud w/o it).. The Y pipe kits on summit were crazy expennsive so I spent a day fabbing my own true dual setup, high flow cats on each side into single in single out flowmaster, 2 1/4" piping all the way back. Hasn't seen a dyno after the exhaust system was setup, I probably lost power though.

 

Also, does anyone have any recommendations on gears? When I bought my car i was told it had a posi in it with 4.56's, which is believable because both tires will light right up, and it won't hook AT ALL. Before I did the top end and just had the carb swap on it, it would squeel for like 4-5 seconds before it took off, if you floored it from a dead stop. Now if you floor it from a dead stop it will sit in one spot for about a second and just burn the tires and then go.. Regardless if they're 4.56s or not, its way to tall of a gear. If I could hook properly I feel as if this car would fair pretty well in the 1/4.

 

i bet it picks up with a holley 650 double pumper and dual 2.5" pipes into a single 3.5" pipe and a bullet dumped in front of the axle. i'd run 4.10's and a 28" tire.

 

Went over my budget by 200$.. so now I gotta wait for my next paycheck before I top off the setup with a demon 650. The car feels so much more powerful though, I don't like the fact that I can't hook from a stop, but I do like the fact that I can light my tires up at 35 lol, that's a fun factor. I didn't do an axel dump because I've always loved the look of dual exhaust out the back, the same setup I had on my trucks. All-in-all I want to thank you guys for answering my stupid questions, and giving me the time of day when I wanted to build my original motor and not do a swap.

I'm not putting much more money into the third gen now as far as power or I'll just lose, it's going to be kept under the car port and driven daily.. that's why I want the demon because they say it's almost as good as fuel injection.

I'm looking into a 4th gen firebird formula right now, with an LT1 in it. I want a new project, and those cars look so bad @ss!

 

Im glad you went roller, that sounds like a sweet build, i'd go 3.73s or 4.10s.

 

i'm glad you were able to jump on it so quickly. makes me feel like i didn't waste my time. care to share any photos or video?

 

I am wondering what my brothers Vette will do after the box stock 500 edelbrock comes off and a good quick fuel 650 and some good gears go in. It has 3.07s and a TH400 with 3,000 stall. Trapped 105-106 mph at the track in 2,600 DA. I think a set of 4.10s and a better carb would push the car into the 12s at 108+ mph and flirt with 110 mph when it cools off. It has block hugger 2.5" collector headers and 2.5" dual exhaust and the only mufflers are 9" resonators. In the picture it had stock emissions era 1980 L82 ramshorns dumping into 2.25" pipes and a 3" single muffler.