Thread: 305 vs. 350

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how much horsepower can i actually get out of my 305 ????? because i wanna whoop some 350's with it , i love chevy but im sick of hearing my 350 this my 350 that ,,,, 305's suck you'll never beat my 350 with one ......... MAKES ME MAD if anyone knows any info on how to best build my 305 will you please let me know???

No matter what you do to a 305, a 350 with the same work will out perform it.

No replacement for displacement.

You can make your 305 peform well. It's really not any different than modifying a 350. It's just another small block, so all the basic principles apply. bore it out a little, get a good stout cam, flat top pistons, 4 barrel, or fuel injection. I had an '85 IROC that was a 305 TPI. That was a fast car, I dig those TPI units, they look good and sound good.

The only problem is, unfortunately, that a 350 with similar build is still going to outperform you. But you can definitely eat a few.

Like others said $ for $ a 350 will beat a 305 ...just the way it is.
I slightly disagree with UROTU about it not really being differant than any other small block.
The 305 shares the same stroke as 350, but has a much smaller bore. Because of the small bore, the 305 has a few limiting factors. The valves are shrouded by the small bores, some will also argue that you cant use 2.02s in it either , cause they hit the cylinders. I personally dont feel a 305 needs 2.02s anyway...it is only 305 CI after all.
a small displacement small bore engine is also sensitive to over camming & over carbing. I think part of the reason the 305 has a bad rap is cause people tried to apply the same hop up goodies to a 305 as they do 350s...& the 305 ended up being more of a dog than when it was stock.
so, a good stout cam in a 350 is likely to much cam in a 305....the 750 that works on a 350 is gonna make the 305 run like a pig.. etc. etc.
if you build a 305 that will whoop up on some 350s...thats cool...but than the guy with the 350 may have far less money in his engine than you do yours...however, I say go for it if thats what you want to do.
I built a mild 305 a few years ago for my 86 caballero...ran 13.70s with 3.08s....now a 350 with the same money coulda ran 13.00s...so, its your call. John

Originally posted by viking
[BNo replacement for displacement. [/B]

This is true!

If you just want a small motor that runs good, do like destroked engine that will turn some rpms!

Maybe a turbo or a blower on a 327 would be another good small displacement combination

! I do get tired of hearing about 350's also so you aren't alone but, a 305 is not the best place to start from!

my dad used to have an 86 1/2 truck with the 305 in it. He tore the emissions off of it and put a stock 300 hp 350 cam in it. Did some tinkering with the quadrajet on it and advanced the timing on it. Had to run premium in it. He ended up selling it to a guy who needed a truck for a paper route. Well his son had an iroc that he used to go out back road racing with. He said that truck was actually quicker than his iroc and ended up driving it most of the time

I'm sorry, let me be more specific. I sometimes make posts assuming that most folks on here understand basic engine building theory. What stepside454 said about camming and carburation is exactly true. But this stands true for any 4 stroke building, and some of the theory drips over into 2 stroke, diesel and rotary. And I agree in that I've seen a lot of guys try to make more out of a smaller motor than it can use, ie: too big a cam or carb, too big ID exhaust, etc...

That being said, when you go to rebuild either one, or any other motor for that fact, first you need to decide what you want it to do. What kind of gas you want to buy, how streetable you'd like to have it etc. The parts behind every motor are different, you are limited by displacement as to many of your choices, from cam to valve size, and from carb to exhaust and everything else in between and other things like what gas station do you want to purchase you petrol at. Do you want to buy av gas or pump gas. When I say get a good stout cam, that applies to the motor in question, don't just go out and buy a big cam for a SBC, get one for your 305. Yes they will all fit, but no they won't react the same in your 305 as in a 350, and a 400 will take more cam than a 350. This is basic theory. It doesn;t matter what motor you are building, vtec honda or BB Chevy, you are limited in what you can use that will actually help. However, the theory is the same and that depends largely on how seriously built you want your motor.

Derek

im new to this and oviously no person needs any logic to infer that a 350 will always make more power than a 305...yeah more power when were talking 700 hp...a 305 can make 300 - 400 hp which is perfect for a steet car or truck...this isnt a track car.... the 350 might save you 100 maybe 200 dollars, even if the 350 block is 400 dollars that still dosent compare to the perfect condition 305 i got for free...look at this http://www.goingfaster.com/spo/325_h...chevrolet.html

http://www.hioutput.com/tech/343hp/343hp.html

http://www.speedomotive.com/sbc_305_...oker_crank.htm

i searched for 20mins and found that stuff....the information is out there, ya just got to look

If you are so tired of hearing about 350 chebbies, than why not build something different??? There's a lot of good horsepower combinations out there, and not all of them are made by chebbie. Yeah, I know. Chebbies are cheaper to build, there's a lot more chebbie parts out there........on and on ad nauseum. If you want something different than build something different!!! How about a V-10 Ford Triton with a scratch built log manifold and 5 down draft Webbers??? Or maybe a track roadster with an Offy engine??? And, don't forget the 4.6 Litre Ford modular motors, with maybe the DOHC heads????? Whatever happened to innovation and imagination??? My current motor projects are a 401 Nailhead, and an FE stroker motor. Ain't no 350 / 350 sbc setups in my future!!! (or past, far as that goes)

Dave is right. Also don't over look inline 6's man! I want to build a inline 6 right now pretty darn bad because I think that the 235's and up are nice for a street rod and you can make some good power and they have excellent torque. They might not pull out any 350-400 HP like a little sbc will but I do know you can easily make 200 horse power from them (Auto Restorer has all this info on a 235 build and the guy made 200 HP with a little exhaust work, porting and intake/carb work. I don't like Ford or nothing (mostly because I grew up with my dad liking Chevy's) but I would love to build a flat head and then now I wish that I could have had a 401 nailhead since Dave gave me some info on them and I never knew they were good motors. There's a lot of different things out there and you can pick up something like a inline 6 for pretty cheap these days and they are cheap to build and still good on gas.
Well I don't wan't to lecture you or nothing, I just wanted to give you my oppinions. Good luck on whatever you choose.

Shawn, if you wanna build an inline 6 that really honks, check out the 300 Fords. Clifford and a few other companies have some really nice parts for them. They will build a ton of torque !!!

Thanks for the info Dave! This 53 I am wanting has a Chevy 235 inline in it but I am still waiting for the guy to get back to me and so far no good but we'll see. I found a truck here that is as close as I can get to my dream vehicle... It's a 1934 Ford truck... They want 2500 but all there is is a frame, cab and bed. Only if I can find a cheap good Ford engine (since I like to keep everything the same such as ford:ford chevy:chevy. I have 2000 bucks but I need that for an everyday driver so now I can't get it unless I sold my dirt bike right away which I would love to do.

Vinc..like I said...generally a 350 will make more power per dollar than a 305, eheather were talkin 250 HP or 500 HP. If you have a 305 & you want to build, by all means go for it. I like to do things differant to, of course when the hood is open, its not really any differant to look at than a 350. Hot rodders dont do things logical, we do things that make us happy. if a hot 305 makes you happy... be happy

Get that 34 ford and put a flat head in it or get a 302 H.O. out of a mustang and switch the electronics that would be different. I saw a hot rod at a show once. It was sitting in a long line of 350 powered cars, but when I got to this one it had a MPFI 3.8 supercharged v-6. It was different and it stands out in my mind. I can't even remember the car, just that it had a v-6 in a line of sbc's. I was also at a farm show and a guy had a Ford 8N Tractor and the was running around and he had a flat head in that too. That was the strangest thing I've ever seen.

There ya go, Bird. Unique is what gets noticed. Most car shows have few surprises left once the hood is open.....Another 350/350, yawn. JMO