[slipfreak84]

what is everyones opinion on a 305 or a 350.....is there really a big difference....i mean will i even be able to tell a difference if i put on it????....what are the advantages and disadvantages of having a 350 over a 305???????.......Thank you so much for whoever responses....

[curtis73]

If you are talking about stock versions of both, don't worry. They are pretty similar. If you're talking about building high performance versions of both, absolutely the 350 wins.

The 305 has tiny bores. Although the 305 has 87% the displacement of the 350, it doesn't have 87% of the performance ability. The small bores means small valves. That means smaller potential.

Think of a 305 as having asthma; constricted airways, which is fine for sitting on the couch or walking around, but for an athlete, it means a serious limitation.

Many times people say that they're going to build their 305 because they don't have the money to buy a 350. They say they're going to build what they have. With the 305, you can easily spend far more money getting your power goals than if you bought three 350s. 350s are so cheap. I have two running 350s that I got for free. I have a 4-bolt Vortec 350 that I bought for $50 out of a 10,000 mile wrecked truck.

[techinspector1]

Yep, what Curtis said.

[slipfreak84]

what all can you do to a 350 to make it better.....if you didnt want to spend a lot

[techinspector1]

Originally Posted by slipfreak84

what all can you do to a 350 to make it better.....if you didnt want to spend a lot

2 or 3 cans of Chevy Orange spray paint might work.

[Alaskan Assassin]

Originally Posted by techinspector1

2 or 3 cans of Chevy Orange spray paint might work.

And some go-fast stripes.

[smrat]

one of those eletric supercharger, bilg blowers, a fake turbo blowoff vavle.

[Alaskan Assassin]

or add one of those things that emit a sound to imitate a turbo... not kidding those exist.

"To make it better" do you mean make a complete engine better or starting from just the block?

My 350 has perfomer edelbrock carburetor, weiand stealth intake, honed, distributor, and it gives me plenty of power for my p/u. I'm sure the orange paint and shiney valve covers help, too.

There's many possibilities to make it better, but first you're going to need to define 'better'.

[slipfreak84]

i just meant like getting a better distributor, or different throttle body or something that could possibly make it better in any way.....im not sure what to do, im kinda new at the whole engine thing.....i just wanted to get suggestions....thats why im on this website, to talk to the guys that point me in the right direction......

[Alaskan Assassin]

Not much to go on..

Budget?
Engine purpose?
What are you expecting from it?

You need to have these established, because theoritcally you could make something that revs up to 20000 rpm with 5000hp and on and on... just asking how it can be made better is not an question that can be answered in a sentence.

[eatonde]

getting some decent heads, intake, and carb HEI is always a good start. I'd ditch the TBI, In stock form they really but a damper on performance and power. I've heard guys say thier 350 feels like it picked up 20-30 HP just by ditchin the TBI and getting a good carb. Now i doubt they really did gain that much HP but i'm sure it helped some.
Like the others have previously said, it all depends on what your goals are?? what are you gonna do with it, tow, drag, circle, street, ect?? there are to many options to start with something that vague.

[junior stocker]

I like Curtis73s' "asthma" correlation. Think of an engine like an air pump, that's all it really is. The easier, and more air it can move, the more efficient it's going to be. That's why things like bigger ports, bigger valves, more cam, boring and stroking, add so much more power over a "stock" engine. There are lots of other little things that can add power also. If you are starting out with a "stock" type engine, then start with the intake and exhaust; free flowing air cleaner, better induction, free flowing exhaust (ie: headers, duals, low restriction mufflers). Later on, things such as a cam change, headwork, precision machining and balancing come into play. But, GEARING is probably one of the biggest things you can do to make any engine work better by keeping it in it's "power band", you'll notice it more in seat-of-the-pants performance.

[curtis73]

As a general rule, "bigger" parts means bigger HP, but it means it shifts the power up in the RPMs. Bigger cam, head ports, compression, carb, intake, etc... it all has to be matched. The nice thing about bigger engines is that you can get that bigger power without shifting things up in RPM.

A stock TBI engine (which is what I assume you have) has the tiniest of everything; tiny cam, heads, TBI (carb), and tiny displacement. They were done that way basically so the vehicle had a means of moving around; not much power, but great on emissions and MPG.

When we talk about upgrading an engine for more power or torque, we are basically banking on the fact that the factory made very mild engines. We can put some slightly "bigger" parts on it and get nice power upgrades without putting the power too high in the RPMs. Factory engines typically use parts that make it suited for low power from idle to 4500 rpms. Street engines use head, cam, intake, and carbs designed for 1000-6000 rpms. Race engines use bigger parts and usually don't make power until the 3000-7000 area. The ticket is choosing the right "bigger" parts so that you match the target use with your desires.

On the street, size is king, so a 350 will be much easier to get your power goals without revving to the sky to get it. Then you fine tune it depending on your use. A performance truck that sometimes tows a boat? You're going to want to keep it on the mild side of that 1000-6000 rpm range. A light-weight Camaro that only gets driven on the street on the weekends? You can get away with a lot more.

The other thing to think about is the rest of the vehicle. You can modify a stock engine a little bit without changing the rest of the vehicle, but keep in mind that torque converter stall, transmission gearing (and strength), rear axle ratio, tire size, traction, rear axle strength, and a whole host of other things come into play. For instance, in that truck, chances are it has a monster rear axle with 4.10 gears already, but the Nova might have a wimpy 7.5" rear axle with 2.73 gears. The more power you add, the more you have to modify the rest of the car to match it.

But... most mild street performance can be dropped in place of a factory wheezer without too much modification.

[mmcs]

I didnt see this question in any reply's (not saying it's not there)

What kind of vehicle is it going in? What tranny are you running? Rear end gears? just making big bang in the motor may also bring big bang in a weak power train, or give you absolutley no major impact towards your goals if all this is going in a 1 ton truck?

Start with the type vehicle, determine what you want it to do, figure in your limitations (ie- budget, availability of parts, gas costs!!!) then start shopping.

One guy here talked about the 350, I agree, you can find them a dime a dozen out there, some of them already built fairly well for a couple of grand, well within any kind of "budget build" price tag. If you ever used craigslist.org, give it a try, I just found a free 350 engine and 350 tranny on there in san diego

[lg1969]

Look at the bright side. When you get all the performance parts for the 305 it will run good. But when the day comes to get a 350. all you need is a empty 350 block. just get a set of 350 pistons. All the parts in a 305 will fit. Manifold, Heads, Ignition, Oil pan, The 305 crank and rods, Cam, timing chain, headers, etc. That is how I build my 350. I took all the performance parts out of my 307. The connecting rods, cam including lifters. I replaced the 307 heads with 202 Heads then transfered the heads on the 350. All I had to get was 350 crank and piston. You can always sell the 305 and get a 350 pretty cheap. If you want to save gas,Then stay with the 305.