Gear install went well..thanks again Bill..it only took me 4 years :D
Car feels great,looking forward to the next trip to the track
Anyway,I should have done this along time ago,but I counted the teeth on my 2.73's and...
it was 41/16 :eek:

2.56's... :eek:

Wow 2.56's

Can't wait to see the new track times. I bet the gear change must have put a smile on your face!

Okay Chris,,,get it to the track!!!

Oh MAN, it's got to feel like a beast! and I had a number in mind, a secret ET guess, just in mind so as not to set expectations or jinx anything...and it was pretty aggressive.

Hehehehe , might turn out to be conservative.

Hell bro, if the "yoke no joke" was fixed, we could run heads up and I'd be slamming gears watching your fender!

anyways, as Arte Johnson would say...

veeerry iintereestink....! graemlins/thumbsup.gif

Oh and NOT FOR NOTHING BUT!!!......

It's like, no matter what it ETs at now or eventually, you gotta keep

12.99 ET turning 2.56 gears in your singature. I mean, that's just crazy silly! graemlins/thumbsup.gif :cool: graemlins/thumbsup.gif

With the 3.31's.it has a real sweet slingshot "effect" when it hits 2nd gear..feels great.Realistically,I'm expecting consistant 12.9X's with the gear swap..now as far as a best,thats anyone's guess..only timeslips will tell.
Keep in mind I've gone anywhere from a 13.09 to a 13.54 with a best of 12.99 with those lazy gears.
I'm still recovering from the 2.56 discovery..my cousin even picked up a few slivers from counting the ring gear even though it was stamped with the 41 teeth count..and man,that 16 count pinion gear is huge too,compared to the 13 of the 3.31 pinion (43 for the ring gear)

welcome to the club...my Buick has 2.56's too !!!!

Originally posted by mc71454:
welcome to the club...my Buick has 2.56's too !!!! ..hey,I just left that club ;) :D
Tom,good luck this weekend graemlins/thumbsup.gif

Good grief! 2.56s!!!! :rolleyes:
What's that...top speed of 160 mph??
Are we gonna see the "new" black cherry run this Sunday?

I bet you get a slingshot effect going into second gear compared to before. With the 2.56's it probably wasn't in it's power range going into second. If you hit a 12.99 with the old gears I would think you'll be 12.5 easy.

Bill,yes I will be running it on Sunday
Looking forward to seeing you guys again too

:D

I left the 2.56 club a couple of years ago myself. I was almost like you. For YEARS, I always ASSumed that I had 3.08's in my '70. When I finally checked the axle tube...VOILA, it decoded to 2.56's. Sumbitch. (I eventually verified this by finding the original bill of sale/other papers. My father bought the car new and the rear end has still never had the cover removed.)

At first I was disappointed. Then it hit me. It ran ok then, but with some gear....looook out. So, I swapped to a completely different rear with 3.91's. Nice difference. Then I pulled the 350TH and went to a 700R-4. Now it launches like a car with a 4.75 gear and 350TH. Big grin. :D

I think you're gonna like it. And yeah, I'd definitely alter/keep your sig to commemmorate your accomplishment. What a testament to torque and the value of a good combination. Hat's off. graemlins/beers.gif

Chris, thats crazy that your running that good with 2.56 gears. Keep us posted and the times with the new gears. What intake and carb are you running? What rpm do you shift at? I still can`t believe that.

My experience with 2.56 gear was when a '69 Z28 came into my shop. The owner had bought it partially because one of the quickest street cars was my '67 Z in our town of 20k. He told me he'd taken it back to the dealer several times but they couldn'd seem to get it right. It had no power! They told him all Z28s were like that because of lack of torque in the low end. I went for a ride and in the first block I knew this car had a problem. He slipped the clutch 50-75 ft getting it going. I asked if I could drive it and took it out to the highway. At 6500 in first gear we were at 90mph. The Mulrooney that came with his car showed he had optional 4.10s. How 2.56s got in it was a mystery but after I propmted him to call the Zone office and complain, Chevrolet made it right for him.

You stick guys can imagine what an M21 and 2.56s would be like even with a big block.

Mr 4 speed, Ive always wondered what kind of time slip you would get with a good gear change, after a 12.99 with huge gears. Do not forget to Post your best time with 3.31's. I'm waiting...

Originally posted by sschevellefan:
What intake and carb are you running? What rpm do you shift at? I still can`t believe that. Currently an RPM and a 3310 Holley
When I ran my 12.99-13.54,it was with a Performer,and I'd shift at about 5000 rpms
Thanks for all the kind words guys,I will post my timeslips from my next track outing.
BTW,the used Powertrax locker continues to live..when we removed the 2.56 gears/2 series carrier,a 3 series open carrier/3.31's went in,and we reinstalled the locker.

Now I don't know if the gear change was such a good idea. Maybe you should've left the 2.56 gears in there and swapped out the 454 for a turbo charged truck diesel instead! Or better yet threw a small 6 banger in there and tried to make it a 30MPG highway cruiser.

But seriously, We will all be interested. I am inclined to think you are going to deal with some chassis tuning issues now that you really didn't face before. A jump that size yields a 29% increase in applied torque at the wheels - kind of like going from a 468 to a 603CI motor.

Your car has been and is going to continue to be the benchmark of what many here would consider a good resto-mod conservative street cruiser. Easily duplicated and not "race-car" oriented.

Once you manage to hook the car - low 12's!

I'm even amazed he ran a high 12 with a 2.56 gear.

My car came from the factory with a 2.56 in it but it had an L65 350 2 bbl.

That's funny about the guy with the '69 Z28 with a 2.56 gear. I bet that poor 302 wasn't even in it's power band. Someone must've wanted better fuel economy.

Now, if i can talk you into 4.56 and an 8" converter :D

Low 13's with a 2.56's is impressive, nevermind 12.99. Freaking "stock" LS5 mill, with some Corwel Special Engineering. Meaning it's built right, smart, and you don't need a damn installment agreement to do it!

CSE = 12.99s in OVERDRIVE

Wow, 2.56 gears, unbelievable. I have a "CSE" 454, an essentially stock 1970 LS5, with the obligatory tall gears (3.08) in the Camaro. Hope to have it up and running this week, and off to the track next Thursday. I'm convinced it's the only way to fly in CA, where most of the driving is on the fwy.

Tony, just get that Lunati cam, no HOWARDS! smile.gif

the CSE uses a good dose of dynamic compression, I don't think it 'll run on Cali 91 octane.

J/K, that was a great 427 buildup btw. Maybe too cheap and easy for the popular media, since I didn't see any mention of it here or elsewhere. Too bad, a perfect K-I-S-S bbc build IMHO. One that your readers would be able to duplicate with ease and no installment payments.

Chris and I seem to be getting away with pretty high calcualted DCR's, 8.45 and 8.58 respectively. Deck height, chamber size, etc, all contribute to the engines being happy there. I use very small OC chambers, while Chris is using Very , very small cc chambers. So if you wnat to duplicate ( Tony, this isn;t for you, I know you got a handle on this), a CSE, you HAVE to be mindful of chamber/dome/height quench, proper cam position/phasing, etc.

The CSE pretty much proves its all about cylinder pressure, as does the completely different HP-type 440, which is making a bit more power than I would have thought.

(more than a buddy's 509ci!!! smile.gif )

Originally posted by mr 4 speed:
Anyway,I should have done this along time ago,but I counted the teeth on my 2.73's and...
it was 41/16 :eek: I did the same thing exactly recently at my gear swap! I wish I had your times with either of my gearsets :D That is awesome Chris - look forward to hearing new results.

it will definately be interesting to see what happens now.
and i thought i was doing good when i ran 8.90's in the 1/8mi with a pretty well stock 400sb and 2.56 gears.

I went through a similar situation. I had 2.56 gears with a 10 bolt open, factory of course, in my '70 Malibu. Then I yanked the 350/350 and put in a built 402 with an M20. I ran the 10 bolt with those 2.56s for awhile until I saved enough for my 12 bolt. I tell you if that would have been an M21 I would have done that clutch no justice. I still had to goose it with the M20, which has taller ratios. Then I swapped in a 12 bolt POSI with 3.31s and, oh boy, what a difference. I have thought about 3.73s, but I drive alot on the highway, so I figured the 3.31s are a good for the type of driving I do.

I love my First Gen. car's posi, 3.31's!!

I can still spin a tire AND still go 70 mph at 3050 rpm with about a 25.5" tall tire....

pdq67

PS., M-20 to boot

WOW 2.56 ! :eek: ,my E/T guess 12.5-12.3 ,a perfect 12.4 car that is thinking in the intake (RPM)change too . :eek: .

when is the big track test?

curious minds want to know!!!!