I want to know how to make some decent power out of a 305 the one i have is from 78-79. so like 130 hp and 240 ft lb of torque. I have a 85 305 off of a monte carolo ss is there any parts i can use off that. I know that a 350 or bigger is a the way to go but i am only 18 and thats what i have to work with.

do a search. lots of info there.

buy a 350 short block, a cam, headers. swap the heads, intake, ignition, etc. from your 305 to that. Upgrade the rest as funds allow. Make sure you have stock dished pistons in your 350 though, the 305 heads will raise compression. It's probably the cheapest most reliable way to double your power. That or forced induction.

Some of the local dirt classes around here require 305's, so they are capable of decent power. Either block will work, doesn't matter really. Buy a set of flat tops for it, either deck the block, or heads, or run steel shim head gaskets. The monte SS most likely has 416 casting heads, those are good. Have them freshened up, 3 angle valve job, guides, seals, springs. The monte should have the factory aluminum quad intake, those work well, should be casting 053. Pick a conservative cam, .450 lift, 214-218 duration area.
If you have any other heads, the 601 casting 305 heads work well also, and have smaller chambers for more compression

Buy a running 350 from a 96-99 chevy pickup for $250. Buy a used carb intake for $100, a junkyard Qjet for $20, a Qjet rebuild kit for $30, a junkyard HEI for $15. For under $500 you can have 275 hp and a decent engine. Add $200 for a cam that will put you closer to 325 hp. So, you're under $700 and over 300 hp.

To get your 305 to make 325 hp, you're looking at more like $2000-2500.

The old argument of "its what I have and I don't have much money" doesn't fly with 305s. These days you can get a running 350 for free if you look hard enough. 305s have tiny bores which limits valve size. Small valves, small breathing. They were a motor that was developed to cut down on fuel consumption, never meant to rev to an RPM that makes big power. You can mess around with all the parts you want, but the fact remains, it will never make the same power-per-dollar as a 350.

The best you can do is mix and match parts and you'll be somewhere between 130 and 180 hp, but that just doesn't make sense. Why tear down an engine and pay for gaskets just to make one engine the same as the other?

The factory heads suck, valvesprings are weak, cams are tiny, compression is low. Getting it to make power will require a comprehensive package that addresses all of those issues, but you'll still have to deal with the tiny bores not breathing well.

There is a reason that seasoned veterans suggest a 350... its cheaper AND better.

By using mostly stock parts, heads, intakes etc., we pull nearly 300 HP out of these motors. Now that's not very streetable, but it's a ways from that $3000 mark too. A milder cam, some port work (not allowed on the ones I build), and headers would go a long way to making that number.

It's by far the ideal setup, and I agree with more cubes when it's possible, but if the kid just wants to play around with what he has, he can get some decent tire smoking power out of it.

I just did a google search for ya.I entered 305 horse power.This is one article I found.Looks interesting,I don,t know how accurate it is.Best of luck with your build.



http://www.goingfaster.com/spo/carcraft325hp305.html

Do a google search "junkyard turbo" "STS turbo" "DIY turbo" try substituting turbocharger, or turbocharging for "turbo" as your search terms.

Two junk turbos ripped from a few 2.5L to 3.8L engines will do nicely.
Some have integral waste gates.
The cool easy effective way to mount a ( or a few) turbos on your car is to mount them at the back where the muffler goes. The turbo(s) essentually replace the muffler in the exhaust system.
STS turbos

I'll leave it up to you to research the details. (if you're interested)

Here's a Tech Tip write up on the 305....joe

Buy a 350. It's the cheapest way to make some serious power.
Building the 305 is a money pit & you'll never see any return from it.
A "Built" 305 will never make the same power as a "bone stock" 350 & the 305 will use more gas doing it with a crappy unstreetable idle to boot.

If miliage is the only consideration the 305 is a better engine.
305's don't respond very well to conventional hop up techniques & parts designed for the larger 350 engine.

Aftermarket intake ports are too large & to add insult to injury the high perf cams are just too big as well.

Essentially all efforts on the 305 will be overshadowed by the lack of cubic inches.
The 350,383 & 400's are really the only intelligent choice when building an engine for high performance use.

The fastest & cheapest way to more horsepower & torque is CUBIC INCHES!

I tend to disagree w/this statement, mainly because it just depending on how well the so called junk 305 is built. In stock form a 305 puts out between 130 hp-250 hp and the 350 puts out between 145 hp-370 hp depending on which stock 350 you happen to buy and remember some Corvettes came out w/190hp 350's in them. OOOH boy that's a lot of HP for that car.
Who gives a rats butt which one he wants to use, they all look the same & unless you're checking the mtr ID number you will never know the difference. And I believe noeljg wanted to use a 305 because it was what he had to use.
Personally I'd put a cam, timing gear/chain and a 4 barrel intake on it & run it the way it is. If you read the tech tip I posted you will see you can squeeze some MPG out of them also. But hey what do I know, I ran a 307mtr w/305 heads, w/a 327 Crane cam & 4 barrel and it ran great w/o any problems what so ever. Best part about 307's & 305's are everyone hates them & normally will give them away just to get rid of them. But then not everyone cares about horsepower, some just want to go down the road. Plus lets not forget what some of the circle track guys are running, 307's & 305's...joe

I completely agree with this. There were stock 305s that could beat stock 350s

I don't care which one he WANTS to use, he just came to us asking how to get his performance with "what he has to work with." We're just trying to tell him that its often cheaper to do it with a 350, even with the cost of buying the additional engine. If he asked, "how do I make power with my 305," that's a different story.

If he was talking about a 302 Ford, that's one thing. They have adequate breathing and they make great power with the money you put in. I wouldn't be suggesting a 351W if he had a Ford 302. But since 350s are so insanely cheap, and it takes far less money to get power from them, there is no basis in the argument of "its what I have."

And what if he wants to sell it down the road? If you put $1000 in a 305 and get 250 hp, how on earth will that return any investment. You can't just look at it from the front of the deal, you have to look at the value of what you have when it sells. If I'm looking to buy a performance engine on Ebay, I wouldn't dream of buying a 305. If I'm looking at a 305 that makes 300 hp and costs $1500 because someone is trying to recoup an investment, why would I buy that when I can buy a 350 that makes the same power for $500 and has way more potential.

Its like restoring a Yugo vs. restoring a 67 GTO. You can put the same money into it, but which one will return more investment if you sell it? In this case I'm not talking about its factual, scientific potential, I'm talking about its street value. I don't care how wonderful you build a 305, its still a 305, and no one will touch it, nor would they sink the premium money into a car that has one. Not only is it a money pit up front, its a money pit out back. Think about buying a used car. Some cars are junk, but they bring a good resale value, while others are super reliable and sell for pennies. Regardless of its actual value, the perceived value is what will kill the deal. Given the fact that there are cheaper, more desirable options like the 350, the 305 sells for pennies regardless of how much power they make.

I've said it a thousand times... the 305 is a GREAT motor... if you don't plan on making it a big performer. Below 5000 RPMs, it has 87% the size of a 350 and therefore 87% the potential. Above 5000 rpms, you'll have to sink an exponentially greater amount of money into a 305 to get the power you want compared to a 350.

This kinda thing just frustrates me. Someone posts with something like, "this is what I have, I want to make 6000 hp, la-la-la-la-I can't hear your seasoned advice." They can learn from their own experience or ours. The fact that he asked us for our opinion means he wants to learn from ours. If he takes it, great. If not, he will end up learning from his own experience. But for him to start the thread with, "this is what I have and I refuse to change," well, he's headed for a financial hole. But you're right... that's his choice.

I still think that getting a 350 short block with little wear, slapping a rering kit in it and putting the 305 top end with a $70 cam is the best way to get started. You're looking at a $600 outlay and it still has a lot of potential down the road.

The 305 short block is good for getting to work or cruising around the lake, that's about it.

is the engine already in the cr and running??

Like any V8 chevy. a 305 will respond well to headers, exhaust, intake, carb, and cam. And these things will also be needed on a 350 so you will not be wasting any money. As long as you are building a street engine, then the same bolt on parts you buy for the 305 will work for the 350.

You can easily make a 225hp/275 ftlb torque with a 305 using the stock block and heads. Maybe another 20 hp and 25 ftlbs if you do a little bowl smoothing on the heads (245hp/300ftlb).

long tube 1-5/8 headers, dual 2-1/4 exhaust pipe, dynomax turbo mufflers, performer intake, 600 holley, and a compcam 240H should make that engine run well (with stock gears and trans and compression).

Pay special attention to the timing curve. Late model hei's don't advance much. you will need 36 to 38 total degrees of timing (with out help from the vacuum advance). 50 degrees total with the vacuum advance.

Then later, upgrade to a 350, 383, or 400 with some good cylinder heads.

remember when setting up an engine....... the compression, gears, stall, cam, exhaust, intake, all need to match.

I have and drive a C-10 pu with a 305 everyday. Of course shes not bone stock. Holley 600, flowtech headers, th350,B&m shift kit, 2 3/4in flowmaster exhaust, 3:73 gears, aluminum intake. I do plan on getting me acrate 350 ************************************************** ************************************************** ********I have centerbolt heads which respond really well to the headers and carb. Just with the few bolt on's I was out maybe $500. The point is 305's dont make big power and if thats all you can afford right now the go for it.
If you dont plan on being on pinks then put a few bolt on's to the baby and keep rolling. I'll put my 305 against any street car with the hopes of just letting them think its a 350.