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383 vs 400 vs 350 vs 327


Guest thepenguin99

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Guest thepenguin99

I know this is loaded question because it is subject to personal preference but here goes anyway. Which chevrolet small block engine would be best suited for a street Z. Almost all use will be strickly street with a little drag racing on the side (very little). I am thinking about 300rwhp will be enough (for now). A carb will be used for simplicity as well as a 700r4 tranny and 3.54 open diff. Any and all opinions are welcome. I did do the archives as well as another chevy forum so im not really sure I will get any new info.

 

the man who changes plans more than underwear

Nathan

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any of the sbcs you named can make 300hp in their sleep.

383-tons of power there, costs a pretty penny, lots of power there.

400-can be found cheap, and its a torque monster, most of them did come with 2bbl and rv type cams though.

350-most available and cheap, all shapes and sizes. very cheap

327-my favorite of the bunch, purely nostalgia, but heres one thing that seperates them from most of the others, steel crank and a forged bottom end stock, they come from the days Chevy didnt know any better but to use the forged stuff, pair that up with backyard ported 202/160 camel hump heads, and a nice cam, carb combo, some tuning, a 2000lb car, and 300hp is easy out of it, and the short stroke of that sucker is music to my ears. they rev slightly faster than a 350 with the stuff on it, but at the 300hp range i dont think there is much difference.

cubes rule, if youre trying to go simple, i would either go with the 350 or the 327. im in love with the 327, its a nice number and it did me plenty fine, i did a ton of drag racing with my old 327z and had zero problems on the bottom end side of things, and very few that had to do with the engine itself.

it all depends on the deal you get and what you can do yourself.

you could always check the swap meets and see waht they got.

you may end up with a 400 block, 350 or a 327, its a crapshoot,

a 350 would be your best bet on availability, i know a least two i could give you that nobody wants, i dont think i will ever have a problem finding one. the 383 is going for bucks.

just my thoughts, and i dont have a v8z anymore, so there.

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Guest thepenguin99

I am leaning towards 327 or 400 from the information I have gathered so far and personal preferences. Like you said, the 350 is everywhere and in everything which makes it lose some of its appeal to me. The 383 just doesn't make sense when I think about it because it costs as much to build/buy as a 400. The 327 I like because its not everywhere, at least not as much as a 350. Lastly the 400 I like because it would make 300rwhp without blinking and still have lots of room for more if I want to go faster later. If anyone wants to correct me go for it...im still a newbie.

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Couple of comments here... Building a 383 Stroker isnt nearly as expensive as it used to be. My shortblock, as documented elsewhere, was relatively inexpensive at $1400, inlcuidng Forged Hbeam rods and forged Pistons and a new Scat9000 crank, all internally balanced and assembled.

That price included an SFI Harmonic Balancer and SFI 153Ring Flywheel. This shortblock should dyno with the heads and induction I'm using at well over 500HP.

 

Scat is now selling INTERNALLY BALANCED 383 CRANKS for Less than $300 (Got mine for $219) which does away with the concerns over not being able to internally balance the assembly, so I don't think is an issue SPIIRIT!

 

On the trackday car we have opted for a 350 build for a couple of reasons... They are a little more forgiving for revs and missed shifts, and I can get all the parts for the same idential build as my 383stroker for Less than $1100. You simply can't argue with that.

 

A word of caution on using USED Forged cranks... You are far better off going with a new Scat crank for $200 than with a used forged crank of questionable history. My engine builder (And Pete's for that matter) stressed this big time... His exact words were "How often do you hear about a forged crank failing at the track???"

 

If you are shooting for a good baseline shortblock package to build 350 crank HP, I'd shoot for the 350 Chevy. Yea, it is common. But that is the attraction to it. They are the most cost effective, and will handle the change in configuration much better when you decide that 350HP isn't enough...

 

Mike :D

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forget what people say about fast revving 327s. The more CI you can stuff into a small block the better.

 

Just like Grumpyvette was saying about the guys he used to race against in the 302 class. He said that no one used to cheat and build a 327! It was always a 350 or larger!

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The debate over the fast revving shorter stroke SBCs (302, 327) versus longer stroke engines (350, 383/400) will likely never end. I have a strong feeling that if a 327 and a 350 V8Z were outfitted with optimum cams/heads/intakes/exhaust/compression ratios/trans-diff gearing the 350 would accelerate faster. How fast an engine revs with no load is not a factor in speed contests.

 

More stroke will make more torque in the same rev range (all else being optimal for an rpm range) and accelerate the car faster.

 

JMO.

(Former 327 revs faster believer)

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...Like you said, the 350 is everywhere and in everything which makes it lose some of its appeal to me...

 

So you want to brag about having a small cubic inch motor like the 327??? Shoot, if that is the case, go 283 or smaller for that 'exotic' apeal, but you'll be slower and wondering how the L6 guy just ran you.

 

I'm not trying to beat you up, but you need to David Vizard's book on building the small block Chevy on a budget. He has some great info on why you go as big as possible. Your 400 ci engine idea is right on track though but they are getting more difficult to find from my own experience. I'd love a good 400 block to start with too.

 

Since I had trouble finding one, I went 350, which is a venerable motor, and can easily be made into a 383 like Mikelly mentioned. It all costs money, but you have to decide how fast you want to go.

 

 

Davy

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I am guessing here....The 700R4 will likely be used in stock or near stock form so shifts will be 5800 or less, so the highest revving of the bunch is the 327 and the potential of well over 600RPM would be lost. The 350 is a great overall compromise in bucks. No bigtime math needed to see the 383 is a bigger engine....or to total receipts. The 400 is weak on aftermarket stuff and is going to be a very low RPM motor. Consider the 350/350HP type setup in cam, intake and compression. Add HEI ignition to avoid points setting/wearing. Street aluminum heads if you have the $ will help handling and power as the compression will be more forgiving of gas octane. The Z is lighter than a full size pickup...be sure the counterman knows what it is going into and what use it will see. I ran a pretty warm 350 with a reworked 700 in a Z for 4 years and it NEVER let me down. Foot on floor 5700-5800 RPM shifts, never broke piece in drivetrain...idled under 1000. The one being built now is LT1...near stock with a T5 for variety...but even with ability to rev to destruction I am not going with big cam etc....street use is street use. Opinions are everywhere so just stay focused on ability to spend/intended use and come up with YOUR solution. Installation costs will be about same and mounts will allow changing engine choice easily at later date except the aforementioned LS1

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How come nobody has mentioned the 302 (except Pete in passing)? I've always thought the 240 merits a more rpm happy motor then a low rpm "truck" engine. A 302 at full song (7,000 rpm) is a better visceral fit to the 240Z concept then a 400 at 5,000 rpm.

 

But, that's just one opinion.

 

Hey, what about a 283?

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The 400 is weak on aftermarket stuff and is going to be a very low RPM motor.

 

Why is it weak on aftermarket? Yes, the block is hard to find (but they are still out there). IF you really want a 400, a new Dart or Motown block is available that'll let you go a good bit past the 400's 4.165 max bore. All the big names in forged pistons make 400 pistons, for 5.565, 5.7, 6" rods.

 

very low rpm motor? With 6" rods, my 400 pistons are 440grams - pretty light. If you are referring to mean piston speed, the 4000fpm limit is the same as for a 383 - about 6200 rpm.

 

Oh, the Probe SRS forged pistons I'm using have the entire ring package (1/8", 1/8", 1/16") above the pin bore. Somebody asked about that.

 

Other than block and pistons, nothing is really different for a 400 versus a 350 or 383. And with the internal balance 383 and 400 cranks out now, the balancer and flywheel/flexplate aren't even and issue. You can put bearing spacers in a 400 block and use a 383 crank (that's what I have) or just order a new Scat 9000 crank with the 400 main bearing diameter journals.

 

Performance advantage of the 400 bore:

The SBC, even the 350 is undervalved even at 2.02" intake/1.60". Add to that the shrouding in the 4" bore/chamber and the flow is compromised. Go to the bigger bore and breathing is improved (2.08 or 2.1" intake valve, with the chamber wall brought out to the bore to alleviate shrouding.) But that's all really for all out power. Not needed at the 350hp range.

 

But I agree that if your going for 350HP, a 350 is an easy economical way to do it.

 

John, the 302 was a great track engine, but to have it make even 350 hp, it'd be peaky. Granted it may be closer to the "feel" of a built L24/28, but some of us would rather have a 6500 rpm limit on the street and the low rpm "truck" torque curve, but from 2000-6000 rpm or so. 283? what's the point? Breathing is compromised (smaller bore, more valve shrouding).

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all the above is well taken...but recall my caveat of $ spent and intended use. Also, The 302 is in my opinion a great motor but NOT behind that 700R4. 302 ( .060 over 283) would be great in lighter car with 5 or 6 speeds. Recall the post asked for what are after all justopinions...mine remains unchanged. john

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Yeah, we all have opinion! :)

 

I didn't read the first thread well. But with 3.54:1 and an automatic, the call for more cubes on the street is even larger, IMO.

 

A 350 will do the job cheapest and easiest.

 

A 283 has a 3.875 bore, a 302/327/350 has 4.00 - that's a .125 overbore, not a .060 overbore.

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:D

 

Well, the 307 crank is the same stroke as the 327, same bore as the 283.

The 307 crank could be used in a 350 block, if someone really wanted a 327. For a 350hp engine, that'd work (it's a cast crank, not forged).

 

Wouldn't it be more difficult to find a rebuildable 283 block than a small journal 327 block, or to put bearing spacers in a 350 block and use a small journal 327 forged crank? large journal forged 327 cranks are a bit rare. But a cast 307 crank would suffice, and you wouldn't need bearing spacers in a 350 block to make a 327.

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Marine engines are a good source for high perf parts. I had a buddy who bought a "retired" 307 boat engine and it had a steel crank. So, there are some steel crank 307 out there, just not passenger car engines. The 307 was available in some 3/4 and 1 ton trucks circa 1968-1972 and they MIGHT be steel cranks.

 

Small journal 4" bore blocks and the steel 3" stroke cranks are VERY easy to find around here. Just no demand for them. That is the easiest way to make a 302, but it should be balanced because the 283 counterweights are contoured for a significantly lighter piston than the 4" bore 302 piston. And forged 302 pistons are STUPID expensive, like L28 forged pistons.

 

My own personal opinion for a "mild", daily driven V8 Z is a 92 235hp 305 TPI 5 speed motor and trans. Should easily push a Z into the low 13's and return nearly 30mpg. If you want auto, look at getting a 9C1 motor and trans. That is the 260hp iron head LT1, and no mods required to the hood latch!

 

This discussion comes up over and over and over in many different iterations. Revability, short stroke vs. long stroke, displacement, etc. Bottom line is the bottom dollar, and the 350 you can make the most power per "cubic dollar" of any of the SBC, followed by the 327, then the 400 IME.

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Guest Carlissimo

Johnc, I am with you and the 302. I have been running a 327 for many years now in my 240Z. If I had to do it again I would go with a 302. It probably will not be quite as fast in a straight line, but it sure would be a lot of fun to peg the tach in every gear.

 

I guess I am one of those few that does not consider the Viper engine to be a particularly attractive sports car engine...

 

....the thread that never ends.....

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custom 383 full roller , all forged, 11:1 cpr,engine CRANE #119661 hydrolic roller (installed retarded 6 degrees) .021 coper head gasket,cam,ported trickflow 200cc heads,(about 210cc now)custom stealth ram, 32lb injectors,custom chip,custom built plenum,58mm throttle body,6" rods, slp forged pistons,total seal gapless rings 9.5 qt baffled custom oil pan,milodon windage screen,jackson gear drive,1 3/4 , with custom merge collector headers, full 3" exhaust, 1.6 erson roller rockers, 200hp nitrous plate,all forged rotateing internally ballanced assembly,fluidamper ballancer pollished combustion chambers,ballanced engine , splayed 4 bolt block, LS7 oil pump,all internals pollished, try that in DD-2000

BTW a stealthram is a 1050cfm TUNNELRAM intake converted to EFI

pictures you might want to look at

 

web-plenum.jpg

engine1.jpg

web-complete3.jpg

web-complete1.jpg

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