[CHRIS SILVA]

Hi there I have a 69 Z with 3/73 gears and a 30 over 302 balanced etc. I am looking to spice it up a bit. Just bought 4/10's to put in, any reason I should not??? I had a big block 68 and miss that big kick in the pants.I am told that this motor will rev forever but I can't get over that feeling that I am hurting the motor. Lastly the four barrel does not open till 4500 rpms is that normal?

[Austin]

My 302 doesn't even start to pull hard till 4500 then goes all the way up to 8500. It does take some serious getting used to, reving that high. Before you do rev it high what cam do you have? Mine has the chevy 302 "off road" solid cam. A beefy valve train should be used with high rpm motors also. My car also has 4.10 gears they work fine, rev about 3500 r's on the highway.

[Sureguy]

Do all of the 302's rev like that? How durable are the motors for reving to 8500? I've heard some people talking praise about these motors but never really knew what they were about. Could some one fill me in. Thank you

[CHRIS SILVA]

Hi Austin yea thats mine 4500 and up it just goes like hell, as far as the motor it is all there solids, etc. Stock including cam the only change is 30 over and balancing it has the stock carb and manifold too. so I think I am going to go with the gears. Thanks for the info. Chris

[YenkoYS100]

I have always heard for years that the 302's were good for 9000rpm's. If the engine is sound, there are only a couple of things I'd think about when doing these rpm's.
1) I'd want a scattershield and steel flywheel.
2) I'd want a Fluiddamper or similiar SFI approved vibration dampner. The stock ones have came apart more than a few times.
Ask Don Garlits about clutch explosions.
Rick
'68 Camaro SS 427
'66 Yenko #YS-100

[Austin]

Ya, I have a steel flywheel and a steel corvette bellhousing. The balancer on a 302 from GM is only for a 302, which I'm not sure how much better they are, but they cost more. I am planning to change the dampner to a ATI though. I also added full roller rockers and a set of stud girdles just to be safe.

[ph ls7]

HI THERE I WOULD LIKE TO SAY THAT I WOULD NOT CHANGE THE GEARS 3:73 TO 4:10 JUST ISNT THAT FAR OFF YOU WILL ONLY SEE A COUPLE OF HUNDRED RPM DIFFERENCE SO WHAT I AM SAYING IS SAVE THE MONEY ON THE GEARS AND PUT A BIGGER CONVERTER IN THE CAM TO PUT THE RPM'S IN THE POWER BAND I WOULD GO 3500 TO A 4500 9 INCH CONVERTER AND AN AFTER MARKET TRANS COOLER HAVE FUN AND GO FAST.

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perry

[gregmontgomery]

I agree about the cam I am a chevrolet tech.for 12yrs.the gear change will make some difference but not what you want the power range of your cam has a more top end range get a cam with a power range of about 2000 to 7000 i recomend a comp.292 installtion well be fairly simple the rewards wiil be what you want. good luck.

[69-er]

Dang!!! 9,000 RPM? Even if the valvetrain would let it rev that high, I just couldn't bring myself to risk blowing a rare engine like that! I think a balance job with some good rod bolts will let the motor safely rev to 6,500 continuously. I race a dirt track 350 and will moving up to the next class. I'll be turning 6,000 to 6,500 RPM to be competitve and I'm scared to death what will happen if I don't build this motor right! Everybody I talk to seems to think that a stock rod w/good bolts will handle that.

Larry

[Trick1]

I agree with not changing the gears I went from 411s to 373s and the difference was slight wish I went with a higher set.
I saw a article in a mag and the only gain from 73s to 411s was a tenth or two in the quarter.

[Trick1]

I agree with not changing the gears I went from 411s to 373s and the difference was slight wish I went with a higher set.
I saw a article in a mag and the only gain from 73s to 411s was a tenth or two in the quarter.

[CHRIS SILVA]

Hi There I think I am going to wait till spring to make a choice. But I am going to restore it this completely winter am leaning to maybe something more than 4/10's.One more thing I do have roller rockers, tell me is it normal to see a good puff of smoke when you get on it? How often should I adjust the lifters? I this the cause of the smoke?

[Racing]

302:s rev,that´s for sure.
8 and a half grand in stock form tho?
Not by a long shot.
Try to get your tach speced.
Now don´t get me wrong!
You CAN get them to rev 11 grand and past that for that matter.

That puff of smoke can be the result of many things at those revs.
Try to make a leakdown on a hot motor for starters.If you rev it by that much,also keep a close eye on the valvesprings bro.
You will kill them by the minute!
Anything past 7 grand can benefit from girdles,no doubt.
I´ve personally tried that Comp 292 grind in solid form on several occasions in the 302:s.
They work great.
Be VERY aware of the LCI when installing the cam tho.
As for 3,73 vs 4,10.
I´m with the other guys here.Not much of a diff really.

Ohh,btw.
The first gen Z:s were all stick.In other words no need for a converter.

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DVC-98.Racing
470 cubes of fogger injected thunder in a 71 z.
racing@mbox303.swipnet.se

[Austin]

RACING
I think you mixed up two differant posts. My 302 does rev to 8500, and I DID state its not in stock form. I have 12.5 slugs and a crane off road solid lifter cam with 108 in. & 116 ex. lobe centerline. My tach is fine I've used other tachs to prove the rpm. The blue smoke is Chris's not mine. What rpm range did you get out of the 292? I'm looking at differant cams but havent choosen one yet.

[sixtsevnssrs]

If it were me I would put the 302 in a crate and put it away for safe keeping. Put a 350 in it. I consider the 302 a peice of history, especially the DZ302.
Unless its a show machine that sees the streets like once a month.
I do agree that the 292 cam will bring the power band for you engine down a lot, and the rear end is fine unless you drive on the highways all the time. What do you intend to do with the car?


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Tim
67 ss/rs, MODIFIED
http://www.geocities.com/motorcity/speedway/6792
IM - sixtsevnss