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anyone run 302 or 327 chevys?


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I have a 302 chevy that i think would be perfect for a z. Does anyone have a 302 in thier z? I know a few people run 327's i did a search and found some info

Do the 327s behave in a z? i think a z would be perfect for a 302, i consider them to the be the king of all RPM motors. Lemmi know guys.

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I have a 327 in my Z and I'm very happy with the way it behaves. The power seems to keep ramping all the way to redline. I run a single plane manifold and drag radials in hopes of minimizing low end spin, no luck through 2nd but 3rd is solid now. With that said, a 350, 377, 383, or 406 would also be nice in a Z. Good luck.

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I have the 327. Power is maybe a little soft on the bottom end but it revs fast and high. 6500 rpms plus time and time again without ever a problem. A sweet dependable motor with tons of power. Your 302 would be great too, I have yet to see a Z with one. I'd say go for it! These z cars are so light I know for sure you will not be dissapointed. Someday if you really want to tear it up punch that 302 out to a 383!......hehe. Good luck!

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Man, i dont want to start an arguement, but i chose the 302 because, like you said, it raps up quick as hell. And to me the 383 is the EXACT opposite of that. Most of the 383's ive been around rap up kinda slow cause of the lo ng stroke. some guys maybe into the tq, but i say, build for hp, and tq will take care of it self. I know i should catch alota flak from that, but try to hold back on this thread. So the low rpm power is soft you say? isnt that good for a z car, too much low rpm power, i think would be useless, no traction.

I would only shoot for 300hp, which i think would be easy as hell to get in a 302, and it would still be fast as shit. 6,500RPM, i heard 302's can go to 7,500 with pretty much stock parts?

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I have a 327 in my car as well but I wanted a 302 for the very reason that you picked it - high revs. With the "image" of my car I didn't want it to sound too much like an SBC. I had to settle for a 327 but with Trick Flow heads and roller rockers I run it up to 7,800 RPM quite often. It's a little "soft" on the bottom end but with a 3:70 rear gear and a T-5 trans it works great in a 2500 lb car.

 

BTW, 302's are getting rare and most of them are usually worth some pretty good bucks because they have all the good stuff in them - four bolt mains, steel crank, etc. Also, I think you will find that 350 to 400 horsepower is pretty easy to come by in a 302.

 

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i heard 302's can go to 7,500 with pretty much stock parts?

 

As always, it depends on what "stock" parts you're talking about. If you're talking about the few and far between 1969 Z28 4 bolt main 302s then, yes, you can safely go to 7,500 without much concern. Those 302s came with:

 

4 bolt nodular iron mains

Forged, tufftrided large journal cranks

Full foating piston pins

3/8" rod cap bolts

Shot peened rods

11 to 1 compression impact extruded pistons

Cylinder head (casting number 3927186) with 2.02 intake and 1.6 exhaust valves

30/30 cam

 

There have been rumors that the 1969 302 made 350hp at 7,000 rpm but, again, its just one of those rumors.

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"...I chose the 302 because, like you said, it raps up quick as hell. And to me the 383 is the EXACT opposite of that. Most of the 383's ive been around rap up kinda slow cause of the lo ng stroke."

 

We had a big discussion on this a while ago, a 383 (because of higher torque) will wind up FASTER than a 302, all things equal. The 302 can rev HIGHER than a 383, all things equal. Here's the thread:

 

http://forums.hybridz.org/showthread.php?t=87072&highlight=short+stroke

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I think transmission choice would also play a big part as well. A 302 or 327 would probably be better suited for someone using a WC T-5, since the engine doesn't make as much low end torque as a 383/400, and can run at higher rpm's to compensate for not having the .5 overdrive of a T-56. A 383 or 400 should work very well in front of a T-56, since it should have the low end torque required to use the 6th gear overdrive. Either combination should be able to attain the required thrust to actually force poop from your body at full acceleration, which is what building one of these cars is all about anyway :)

 

Mike

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A 302 is a 327 with a 283 crank. A friend has a 67 camaro with a 302 built out of a 327 block and 283 crank stock eliminator and is almost in the 10s in the quarter. From what he is telling me there is a large and small jornel cranks.

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If you are really married to the idea of a high revving 302 and are on a budget, then move over to the "other" V8 forum and look at 5.0L Fords. Light weight, plentiful, roller camshafts, and they make great HP. Really great HP if you use aftermarket heads.

 

g

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I have a Good friend who's Father has a 1971 240Z with a DZ 302/Richmond 6 speed in it. The DZ 302 is also Supercharged/roots style. That car revs to 8k plus and is a real treat. Very fast as some unsuspecting Cobra Mustangs have found out. By the way the blower is a little 144 mini.

 

Mike

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I have owned a 302 and a 327 both in the same car, the 302 was softer on the bottom than the 327, and both pull hard from 3k up, neither will really quit pulling if you keep your foot stuffed in the carb. My boys z has an overkill 357 in it now and it rev's so fast it's hard to believe, but thats cause the tires are spinning.

 

Stock parts going 7500 rpm. Yes, that is true, pretty reliable, yes, that is true also, totally reliable, no, that is not true, depends on alot of things. I think anybody on this forum will agree that first the stock rod bolts should be changed in favor of SPS, B&B, or ARP bolts, beams cleaned up of casting flash and magnafluxed is the best way to prep, and hypers or forged pistons for anything over 6K, but nothing is stronger than forged and for a few dollars more, it may be cheap insurance like the bolts IMHO.

 

Stock steel cranks are found both in small journal and large journal. You can find a steel 307/327 large journal crank in some P/U truck engines. 283 small journal cranks steel cranks can be found for $50. The 283 "HB" block can be bored safely to 4 inches, hard to find block, I only have one left, they are small journal and you can put a 327 crank in that 283 block only. All others have to be excessively clearanced for 327 counterweights and you usually hit water, not all the time but "usually". Eagle makes a 3 inch and 3.25 inch stroke cranks for $500 in large journal and you can use 350 four bolt block and make you a homemade "DZ" replica or 327.

 

You'll find that the 327 and 302 make good power with stock type heads, like the camels and aftermarket Dart and World castings. Obviously they will make even more power with heads like twisted wedge, Edelbrock, brodix and the venerable AFR HP king of the hill. If you oversize the heads, it really takes away low end and midrange and focuses power in the top end in the 302.

 

I sold my World products pro ported 72 cc/ 200 cc intakes heads with Manley raceflow +.100 2.02/1.6 valves, isky 9365 roller springs, Comp +.050 steel 10 degree retainers, Harland sharp 1.6 roller rockers, screw in studs, guide plates, stud girdles, custom roller cam 260 duration, .630 lift and a NIB set of Comp .080 roller cam pushrods for $840 complete last Friday, so if you watch you can get a good deal! I had them listed here on hybrid z and Ebay but had no interest.

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The Z-28 blocks were large journal 4 bolt.

 

Only the 1969s had the 4 bolt. The 1967s - block casting number 3892657 - and the 1968s - block casting number 3914678- were all two bolt mains, but the 3914678 casting did have the large journals.

 

EDIT: Forgot to list the 1969 block casting numbers: 3932386, 3956618 and 3970010.

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Guest 77vegasz

I know I will catch all kinds of hell for saying this, but my Z is on it's thrid engine. The first was a 307, which I got for free. I rebuilt it to 10:1 compression, used the GM 350 HP 327 cam and a set of ported and polished 305 heads that had been resized to 1.94 and 1.50 valves. This little motor reved up fast ran hard and was a blast.

 

I then made a 327 using the 307 crank and a 350 block. I reused the 350/327 cam and heads. This motor performed about the same as the 307 with only a little more bottom end. Both made around 340 hp at the crank.

 

I now have a 475 hp 389 (4.060 bore, 3.750 stroke) monster. It is fast as hell, but tire spin is an issue and half shafts are taking a beatig.

 

I ran a B&M Turbo 350 with all three motors, and must say that for a daily driver, the 307 and 327 were a much better choice, and behaved much better. But for wet your pants performace and incredible burn outs, the 389 has proven to be the ticket.

 

Jon

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