Well i was going to build a 383 stroker for my 83 z but lately i been thinking that 383's kinda have horrible gas mileage.. and it won't be " stocked" so i decided im going to buy another 305 block and have freinds help me build a juiced up 305... but i have one problem... I know nothing about re doing engines. and i want too build my 305 into a fast one.. and put a stroker kit in it. so it will still be a 305 engine block but with a stroker kit. Can somebody tell me all the parts i need to build a kick *** 305?

 

Well your probably going to get flamed by alot of people saying go 350, but if you want a 305, thats your choice so I will help you. If you do a little searching around there are stroker kits for a 305, pretty much a 383 kit but in a 305 with a .030 over it will be a 334ci. I think any 383 stroker kit will work but I'm not positive. Then you want some good flowing heads, this where it gets sucky for a 305, its pretty much stock heads, TFS 56cc heads, or Word Products 305 heads. For the money a set of stock 416 castings cut for 1.94's and a mild port will work great, I'm sure five7kid will back me up there. Next is camshaft, it depends on what your looking for, IMO something with a duration of around 214/234 @ .50 would be a nice torquey cam with some decent top end. Maybe a little more cam, depends on what you want. Do you plan on running carb or EFI, if your staying carb, you can have your Q-Jet tweaked to perform just fine, or go with a holley 650 and a good single plane intake. If your going EFI then a good TPI or HSR setup would be nice. Then there is exhaust, some good 1 5/8 in. primary tube headers with 3 in. collector and 3 in. pipe all the way out will be plenty. Thats pretty much the basics, now you just need to decide what you want. One other thing is your T-5, if you plan on making some decent power out of this motor your T-5 wont take it for long, so consider that. I will tell you this once, dollar for dollar a 350 will make more power than a 305 with the same mods. But do what you want to do. My

 

305 stroker kits and 383 stroker kits are different. Different bores.

383 and 334 kits cost the same, some places the 383 is actually cheaper.

Blocks cost the same. Either way, you're still going to pay for machine work.

Without looking at casting numbers, no one can tell a 305 from a 350. Build a 383 and tell them it's a 305. I usually tell people my 406 is actually a 302. Saves the "high revving" explanations.

Do a search. There's countless 305 stroker threads.

 

oh... well i don't know i was thinking about the 383... but im going to be spending way more money on buying gas to fill up my car... and i was thinking that the 334 would save me on gas?!?!????

 

and when i building my engine do i need to add something to the engine to make it a manual? i might get flamed but i kinda want to turn it into a automatic.... do i need to do something different??

and i keeping it a carb what carb do i need for a 383?

 

How much gas the motor uses won't be too different. Has a lot to do with driving style and how hard you get on it and how often.

For a manual transmission, you get a flywheel and clutch. For an automatic, you have to use a flexplate and torque converter. If you look at pre-balanced kits from most vendors, they come with flexplates anyway, flywheels being an upcharge.

 

350 shortblock or 383. The stroked 305 just doesn't make sense either from cost or performance.

A 350 has more cubic inches than a stroked 305 (334 cubic inches), and fuel economy will be about the same. Use the money you didn't spend on the 334 and buy gas for 5 years.

 

what would be better to buy a used automatic transmission or a brand new one? or i guess just a rebuilt one with a shift kit? are shift kits worth having if your not going to race?

 

No reason a properly rebuilt transmission wouldn't work. I doubt you could find a new one.

A proper shift kit can help the transmission last longer. B&M doesn't seem to quite have a handle on the TH700R-4, though.

 

i just might go with the t56... only problem going to take me awhile to save up the money for it.. engine and tranny my very last project for car...

 

Well if your not looking for a monster v8 something small with some good punch why not a 327 or even a 302 (chevy NOT Ford!)? The 327 almost the same displacement as a stroked 305 just way better. For startes its got a short stroke with a big bore ive heard stock ones going 7500-8500 rpms a stroked 305 or even a 383 cant touch that without some serious work due to the long stroke. Its got the 350 bore so you can use larger valves than on the 305. With a steep rear end it would make a very formidable performer. The 302 has all the same advantages but an even higher max rpm but less dissplacement.

 

8000 RPMs on the street is 100% useless in a car.

Go 383. Make more power than a short stroke motor. Spend less. Have a happier, more street friendly engine. That's about all there is to it.

 

Well 8K rpms on the street is pretty useless. Actually its about as useless as a 383 for daily driving. Now theres no debating that a 383 will yeild more power and torqu than a short stroke motor like a 327 however the objective is not to build a motor for all out performance. The goal is to build a motor with a bit more kick than stock maintaining good driveability and respectable gas mileage. Concidering hes probably used to a 150 hp 305 i would say if hes looking for "a motor with a little more kick than stock" a 250-300 hp motor would make him very happy. This is very easily achieveable with a 327 or a 350 also with a 383 but the 383 is way overkill a 250-300 hp goal. Next is reliability sure 8 k rpms on the street isnt real pratical but most of us at one time or another have taken our cars up to 5.5k the rasors edge for a run of the mill 350 that has a shorter stroke than the 383. A 327 taken to 5.5 k will take it like a champ because it can be run up to 8 k without a problem. So its a matter of reliability and long term longevity. Also he does intend to change the trans which is an abosolute requirement for running a torque monster like a 383 but what about the rear axle? A respectable 383 will tear the factory 10 bolt apart under enthusiatic driveing conditions. A 327 is not a such a torque monster would obviously benifit from a stronger drivetrain but will much easier on the drivetrain. So for the given goal a 383 is just unapropriate given the goals he has set up not to mention more costly than just getting a 350.

 

Buying a 350 rotating assembly is no more or less expensive than a 383. Last I priced out a kit, they were pretty much identical. That said, then no, there is no price difference between a 350 and 383.

300 hp on a 327 requires more aggressive parts than it does on a 383. Less aggressive makes better street manners. A properly built 383, even with a cast crank and proper rod bolts can see 6k.

RPM limits in 99% of street motors have nothing to do with stroke. Airflow limits how many RPMs a motor turns.

 

True useing less aggressive parts will give you a more well mannered motor for the street. But look at the TPI 350s from the factory put out 240 hp and the manners dont get much better than that. A mild 350 or 327 could easily get into the 250-300 range. A 383 would have to use some pretty small parts to get down into that range. Its been done..... in the mid late 70s where 400 ci + motors put out 200 hp but chokeing it off to that point just isnt very efficient by any means. So it could do it but at that rate really whats the point of going through the trouble for a 383? Also true buying a rotating assembly is about the same for a 350 or a 383. The problem is buying a rotating assembly does not give you a 383 you still need a 350 block (concidering hes only got a 305 right now). So you can buy a new 383 crate motor that will genrally run about $1000 more than an equivalent 350 or buy a 350 used and have to have it rebuilt and install a 383 rotating assembly which again is more expencive than just having the 350 rebuilt. Where as you can get a 350 and be done with it. Also the cost of the rotating assembly is just one part what about the machine shop costs for clearancing? Not needed with a crate 383 but again there like $1000 more than a crate 350. A 350 again will just be a 350 no addition work requires no small based cams nothing just a regular SBC. So no matter how you cut a 383 will cost more than a 350. That being said for a real performance build up its worth every penny but this isnt. Your also right the rev range you run in is typically defined by the parts used and the RPMs they are designed to work in but again in any even a mild perfromance build will be rated up to atleast 5.5k RPMs the typical max RPM for a 350. Some people go even more aggressive 2k-6k or 2.5k -6.5k which is useless on a motor that red lines at 5.5 k. Even if a well built 383 is capeable up to 6 k in a performance application it will see thoes kinds of RPMs from time to time even on the street and a well built 350 will be able to get more than 6k and further more a well built 327 will be capable of going even farther. Not that you have to but a motor thats built to run 8 k rpms will last a lot longer than a motor that maxes out at 5.5 k rpms if they were both run at 5k constantly (or just run hard throught there lives). Now all that being said a 383 is a great performance motor with tons of potential with gobs of torque but i think in this case its just totally unneccessary like sending in a tank to settle a domestic dispute and concidering his lack of experiance with engin building should stick to something allittle easier.

 

Stroke has absolutly nothing to do with maximum RPMs on street motors.

It's not about mild, it's about manners. A 383 can take larger cams and head runner volumes and it will be far more mild mannered than a comparable 327.

Buying a 350 block and DIY clearancing is no big deal. Ask the throngs of people on this site who have done it, including myself. Several times.

Buying a 350 block and going 327 with it would also require buying a rotating assembly. No different than a 383.

The short stroke vs long stroke has been beaten to death here: https://www.thirdgen.org/forums/engi...t-fiction.html

I suggest you read that.

 

Stroke absolutly does effect max RPMs. Granted there are other things like the valve train and performance parts used and quality of parts and machining but reguardless there is a maximum piston speed and short strokes allow for higher RPMs or lower rpms with reduced stress thats a flat out fact. Yea a 383 can take bigger cams and larger runners without sacraificing driveability because its a larger motor and natrally larger cams and runners will work nicely because its a more appropriate cam or runner size. Yea the can also tolerate larger amounts of overlap. However a 572 can take an even larger cam and larger runners with a smooth clean idle and good torque but that does not make it a good choice for a daily driver. Buying a 350 and getting a 327 rotating assembly also does cost as much as a 383 however who said anything about buying a 350 and converting it to a 327? It just wouldnt make sence concidering 327s already exsist and the primary reason i suggested the 327 was because it was close to the displacement of a stroked 305 otherwise i would say just get a 350. This isnt so much an argument of long vs short stroke this is an matter of whats the most approprate size motor given the desired end result a 383 is just over kill. If he wanted 450 hp and wanted to stay with a SBC sure a 383 will do that much more efficiently than a 305 but if you wanted 200 hp a 305 can do it way more efficiently than a 383. Yes its also possable to do it yourself clearancing just like porting and polishing rebuilding motors ect but for someone whos new to the game is it really a good plan to have them try and experiment on their first motor build who has very little knowlege of the subject?

 

Fuel economy is all in how well the combo components are matched to each other, and driving style. I can make my 400hp 355ci with the big Holley double pumper get the same gas mileage as my stock 290hp LT1 in my daily driver if I want to. Look up the window sticker for these cars... the 5.0 and 5.7 cars are rated almost exactly the same for MPG. I think there was a 1mpg difference on the city rating. Transmission choice can make a big difference too... my 4bbl 350 gets around 16-18 on the highway, because its got a non-OD trans and a tall rear gear. My LT1 gets right around 30 on the highway with a shorter (higher numerically) rear gear because its got the T56, which has 2 overdrive gears.

A bigger engine will make more more power in a more useable powerband, make ALOT more torque, be more reliable and more user-friendly to drive around town. Being that bigger typically means lower revving, it will also last longer and won't be as hard on parts. For example, my XE274 cam in a 327 would really need to rev to make good power... easily a 7000rpm engine. The same cam in a 383 would make the same or more power, loads more torque, but probably top out around 6000rpm. The fuel mileage difference would be very little if any.

The mileage difference between engines sizes withing an engine family are pretty minimal, assuming the build is otherwise pretty similar (similar size cam, similar cylinder heads, intake manifold, etc).

 

Well i can half agree with you. Fuel efficiency is determined by how well parts are matched. I can match up some parts very well to make a 350 put out 450 hp at 6.5k or i could match parts to work well to produce 300 hp at 4.5 k one of these motors will have a significatnly better gas mileage car and drive train being equal. Driveing habbits will also effect gas mileage but again useing the exapmle earlier one of thoes engins will get far better gas mileage still. Furthermore a 454 in a chevy blazer will probably get better gas mileage than with a 4 cylinder. So when i talk about gas mileage i talk in terms of all things being equal except the motor some combinations will have better gas mileage than other. So really is about picking the right size motor for your given application. Now in your example of useing the XE274 in a 327 and in a 383 the 383 there is no question will develop more useable low end torque than the 327 and the 327 will have to scream away to perform in its power band. Although its not really a fair comparison an XE278 might be approprate for a 383 but is too large for a 327 an appropriate cam for the 327 will produce much better low end torque not as much as the 383 but this leads into my next point. To make hp theres 2 things fundamentally that effect hp volume and efficiency and if 2 motors have parts appropriatly chosen so they have roughly the same efficiency then the one with the larger volume of AF mixture will make more hp and also have worse MPGs again car drivetrain driveing happits being equal. So if you were looking to produce like 250-300 hp a 327 or a 350 can do that without useing radical parts to maximize efficency while useing the least volume. A 383 on the other hand would have to be eather A. detuned like cars of the late 70s which were terrably inefficient for the most part to get down into that HP range or B. allowed to exceed the goal HP with decent efficency useing mild parts also. However this in turn will decrease gas mileage and on a daily driver that will never see the strip whats the point in sacraficeing gas mileage and spending more on a motor if youll never really put it to use? I guess thats where our oppinions very my stick shift 425 hp 83 z gets about 15 mpgs on average city vs highway where as my stock auto trans am whos fuel economy could be greatly improved with the use of more appropriatly sized parts and other parts headers/ exhaust that my z has ect still gets an additional 5 MPG on average and i belive i can get it to atleast 25 MPGs on average with a better cam exhaust ext. Thats like 10 MPG difference. For a street car thats a big difference. Again different cars have different weight different aerodynamic drag gearing ect but im speaking all things being equal. So basically with all these posts all i was trying to say was that his HP goals could be met efficiently while maintaing good gasmileage and streetability with a 327 or a 350 better than say a 383. Again 383s will have better hp and low end tq and if he was looking for 350 or more ide kinda lean twords the 383 but for 250-300 i think a 383 too much.

 

No, stroke has nothing to do with RPMs on a street motor. It has everything to do with how much airflow the engine needs versus how much airflow the cylinder heads are capable of delivering. A 327 needs nowhere near the amount of air a 383 requires, thus, it is able to rev higher on less air supply. The larger stroke of a 383 obviously has more volume to fill, thus requiring a greater amount of air to hit higher RPM's. Why do 350 TPI motors choke out at lower RPM's than 305 TPI motors? Because they require more air, but the runners and baseplate are still the tiny straws, unable to supply. I have a 406 Sb2 that can hit 8k on demand. Same stroke as a 383. Massive air supply gives the RPMs.

Piston speed, piston dwell, blah blah all those things due to the geometry behind a 327 have nothing to do with RPM. They have everything to do with sustained RPM endurance and efficiency of the motor. There is no limit on the speed the piston is going to travel. Either way it will move up and down, until the point where the cylinder heads are unable to move enough air to adequatly fill the chambers inthe given time that the camshaft allows.

 

Clearly a motor that cannot flow enough air will not rev up any high limiting the RPM. Just like if you run soft springs valve float will limit the RPM. There are other aspects of a motor that effect max RPM but piston speed is one of them. There is a speed depending on many factors that if you exceed the bottom end will self destruct. There will come a point where you will develop a rod knock or worse yet throw a rod. The pistons will not simply go up and down reguardless of RPM there comes a point where things will break. Now lets say you do exceed your piston speed on a launch and nothing broke does that mean piston speed means nothing? Like you said at thoes RPM endurance is a big factor but hardly anything in this world just has a catastrophic failure only when severly overstessed. Most things that are overstressed will fatigue untill complete failure example exceeding the piston speed of your bottom end. Sure you can do it but for how long? a 383 might go up to 7.5 k but for how long befor a failure? A 327 can sustain thoes RPMs. Of coarse this is assumeing proper air flow and valve train. So to me if your bottom end is self destructing youve exceeded your rev limit. Kinda like i can put a huge intake and cam with good springs for high RPMs but on a factory cast crank on an SBC i wouldnt try to run it a 7k for very long.

 

If you're not keeping the same engine block in the car, it won't be original...

If you're switching out the 305 for another 305, go 350.
The parts (rotating assembly) are more expensive (because there are less people doing this) for a 305 stroker than for a 350 standard or stroker...

You'll get more power & better priced parts with the 350.
Not that it can't make a 305 fast, it's just more expensive & by design, not as powerful as 350 (please see numerous beaten to death topics)...

I've been weighing options for myself, I have a 305 TPI & I want to mount my Procharger to it... Being the engine has 150k miles on it, I would either need to redo my 305 or put in a new 350... My 305 is 2 bolt mains... It could get converted over to 4 splayed, but that alone is a few hundred dollars... Then the cost of the 334 stroker kit (which is about $500 more than the 350 ones I was looking at), plus new heads, etc...

I can start with a 350 block 4 bolt main & all the parts for it will be cheaper than the 305 + MORE POWER!.... I am going the 350 route... Another side note... I haven't seen any 305 blocks for sale by GM, Dart, World Products, they all start @ 350ci... (at least at all the online reptilians I've been checking out)

Rafael

 

The easiest way to go fast and maintain decent fuel economy is to go LS1.

A fast 305 will not get good fuel economy.

SBC's are not particularly suited to going fast and getting decent fuel economy.

A car driven fast does not get good fuel economy.

Stroke has very little to do with power or fuel economy.

An engine capable of 8000 RPMs (at least still making power at that RPM) will not get good fuel economy.

There is no free lunch.