Thread: Old Chevy big blocks vs. the newer LS1 and LS2 motors???

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Never ran a Nash, but I hear their great. As for calculating the ratios, its really pretty easy. I searched the web and found no less than 12-15 different (and free!) calculators and I input my numbers to determine my highway speed vs the necessary gears I would need. After several attempts (I couldnt believe my eyes because Im running a ZF-6 speed out of a ZR Vette I found at a swap meet) I finally opened up excel and built my own. (I'll send it to you if you email me and ask).

To my surprise, the other calculators were right after all. With 4:11s and 30.5" tall tires, I still have to run 75-80 mph to justify 6th gear. 4th is 1:1, 5th is .75:1, and (sit down for this one) 6th is .49:1. In fact, at 100 mph, she turns 2300 rpm (barely awake). So you can see just how streetable a stout horse can be. No one believes me about the gas mileage so I wont even mention it (until we hit the road and they see the gas going in and the miles coming out that is).

So I guess I would recommend putting your money in the tranny and keep your ponies. You can have your cake and eat it too!

I haven't heard much about the ZF-6speed trans from the Corvette.Is it similar to the Viper T-56 trans and is it strong enough to handle big block torque and power?? That 6th gear would really keep my RPM's down.

I guess it can handle the big-blocks, it was engineered for the ZR-1 and is rated for 450 horses. They dont call it "the rock-crusher" for nothing.

They are hard to find as they only came in the vettes, no camaros/firebirds. The T-56 is a completely different tranny. I think Borg-Warner makes it (if my memory serves me right, when I went looking I quickly eliminated the T-56 due to its horsepower weakness).

As for the ZF (Zingenfelter), it is made in Germany and lord help me if I ever need it worked on. I have been told you either have to ship it overseas or find someone in the states who is familiar with them and is authorized to buy from Zingenfelter. I paid $1,700 for mine used and then spent another $500 for a centerforce clutch. I have been told I got a great deal. I just hope it never breaks.

I know that ZFs are very popular in the trucking world although they are completely different than what we need for the old cars. But many service shops can work on the autos if you can find one. The great news is it will simply bolt up to your big block.

Good luck and let me know if I can help.

I just thought of another option for you that wont sacrifice strength or cost more than anything youve mentioned thus far.

My brother is building a '46 Ford Sedan with a 460 Ford Crate motor. Fords arent known for their Overdrive muscle so he opted for a Gear Vendors Overdrive which simply attaches to the tail-shaft of an automatic tranny. Not sure if you like automatics or not (I think real hot-rods have to have 3 Pedals, but hey, what do I know?), but this is a good way to go if you do.

By the time you get your driveshaft shortened and install the GV, you would probably spend $2-3K with a beefed up tranny.

Just an idea......

Sound like you got a special transmission there in the ZF.I wonder why the T-56 would not be enough especially when the Viper has 500 horsepower and i bet I am at 425-450 max.Do you powershift your car.I have a 225 Horse power Mustang Gt 225 Horse and i tried about 10 times to powershift on it and it finally broke 2 tranny's in 1 week.I have never learned how to speed shift either.Speed shifting puts much less stress then powershifting.Just wondering how you shift in your car??Doug Nash and Richmond's sound interesting also but I won't be able to find a ZF and when it breaks no one can fix it here in the states.

You can find them, but there not easy. And you can get them worked on, just not around the corner. But I certainly understand your point. I just hapenned to have gotten lucky. Could probably never run across another ZF if I tried. Besides, they are very heavy and very big. It takes a lot of work to fit them in.

As for speed shifting and power shifting, Ive never hit this old car that hard. A metal '34 that we've had since 1965 and logged over 270,000 miles (and still counting) is just too sentimental to risk. The ZF is built to skip 3rd, it even has a built in signal to light the corvette dash so you know when to go from 2nd to 4th.

But I have had a Borg/Warner T-5 speed before hooked to another 383 small block and I never had any problems with it. I guess I am more of a highway freak than a red light-to-red light guy. Not that I don't every now and then, I really enjoy going 80-100 mph down the long open roads.

I have heard of several people putting the T-56 behind big blocks without issues. And Im pretty sure the DN would be stronger. Still, the way I see it 5 or 6 gears are the best way to go.

My best bet would probably be the Doug Nash 5 speed.I wonder how many different transmissions they make as far as gear ratio difference in every gear.I never see that transmission listed in my Smmit catalogs though.They are probably over 2,000$ as well like the Richmond's.I would have to find out some way about what gear i should run if i go with a Nash.Do you know if its easy to swap a Muncie for a Doug Nash Trans?? I know I will need a new shifter.I would have to get somebody to install it anyway.

I did a web search on Doug Nash Transmissions and came up with the link below. I guess Richmond bought out Doug Nash, still lots of good info on a swap, even if it is into a Vette.

http://ncarboni.home.att.net/TrannySwap.html

You could still looks for one at swap meets etc. Maybe even Ebay if you wanted to go with the oroginal Nash.

Pat

In fact, here ya go!

http://cgi.ebay.com/ebaymotors/ws/eB...spagename=WDVW

Good luck with your project

Pat

Thanks alot for all the information.I thought the Nash might have been the Richmond's Tranny's now. Right now though I am low on money but in the future hopefully within 6 months I can make a good decision on a good strong tranny.I preferably would like to buy one new then at a swap meet because I am not a guy who can tell if the transmission is in good or bad shape just by looking at it.The last Muncie I had exploded.I could see when I looked inside and saw all metal pieces in it.BUt that was easy.A used tranny with a bad Synckro might be hard for me to judge because im a beginner when it comes to inspecting a transmission.

69muscel,

I was on eBAY looking for Halibrand wheels and found a ZF 6speed for sale. The current bid was $2,000.00 but it could be bought for $2,500.00. Either price is good for a "new" tranny. Especially considering the strength of the ZF.

Just thought you might like to know...

Thanks for letting me know.To bad Im low on money right now though,but Im not in a big hurry yet anyway because I would like to get the car on the road by next spring.