Auto tranny ?'s

[GloryHound]

I'm doing a frame up rodstoration. Right now I have a TH350 Lock up sitting on the shelf, but I am thinking of going with a 700R4. I was wondering what the advatages of each of the trannies would be for a swb sbc truck? What type of rearend ratio would people recommend? (remember I live in PA the land of hills!) I would like something that I could romp on and get some acceleration out of, but ultimately I want to use the truck for road tours.

Thanks for your help in advance,
David

[bowtie]

Well the biggest advantage is that you can drive on the highway with out your engines reving real high. There is a bit of a gas saving (although not much with a BBC) if your highway driving. I have 373's in mine and I drive it everywhere.

Go 4 it

[mrein3]

Originally Posted by GloryHound

I'm doing a frame up rodstoration. Right now I have a TH350 Lock up sitting on the shelf, but I am thinking of going with a 700R4. I was wondering what the advatages of each of the trannies would be for a swb sbc truck? What type of rearend ratio would people recommend? (remember I live in PA the land of hills!) I would like something that I could romp on and get some acceleration out of, but ultimately I want to use the truck for road tours.

Thanks for your help in advance,
David

To answer your question directly, since you have a small block (sbc), I'd put a 700r4 in if you have 3.73 rear end gears. I'm assuming you have a 2wd truck since you didn't say 4x4. Even if it is a 4x4, with 3.73 gears, I'd go with a 700r4.

If your rear end is a 3.08, and you are planning on not changing it, I'd seriously consider the lock-up th350. The overdrive gear on the 700r4 is .7:1. That is, on paper, a 30% reduction in rpms. The 3.08 gears give approximately a 20% reduction in highway rpms compared to the 3.73 gears. ON PAPER, that lock-up th350 with 3.08 gears is just about right.

A 700r4 with 3.08 gears might drop your highway rpms way too low.

For acceleration, the 700r4 has a real low 1st gear but the drop from 1 to 2 is big which would end your fun early.

[355]

I have a 69 lwb step = Heavy. I run 3.08 w/ a 700 with a lockup. Tire size is 255/70. At just under 80 mph my tach is 1800 rpm. I have no problem with the Eaton LSD smokin the tires and this week comin to work I got 16 mpg.

[mrein3]

Originally Posted by 355

I have a 69 lwb step = Heavy. I run 3.08 w/ a 700 with a lockup. Tire size is 255/70. At just under 80 mph my tach is 1800 rpm. I have no problem with the Eaton LSD smokin the tires and this week comin to work I got 16 mpg.

Good point 355.
If you normally travel 80mph, a 3.08 with a 700r4 may work. My commute has a 15+ mile stretch where I set the cruise on my daily driver to 80-85mph depending on the traffic and conditions.
If all the roads you travel are 55mph a 3.08 and 700r4 may not be the best choice.

However, don't forget you can manually select the 3rd gear on a 700r4 which is 1:1 like the th350's last gear and the tourque converter can lock there too.

[GloryHound]

Sounds like the best way to go is the 700R4. Does anyone know anything about the 4L60E trannies? Are these as good as a 700R4? Anyone know of anybody or place that would trade a Th350 lockup and a Regular TH350 for a 700R4?

[Gray Ghost]

I will have to be the voice of reason. I'd stick with the TH-350 or 400 if it were me. I've had three OD trannys and they all OD'ed rather easily under power. None of them (two 700r4's and a 2004r) were worth a darn and rebuilds cost a fortune ($1200-1600). If you have a stock smog motor and don't ever plan to drive like anything other than your grandma...get a 700...otherwise, use the savings you'll have to help pay for gas and get yourself a good 350.

Now the 4L series are much better trannys...especially the 4L80E. If I could afford one I'd drop one in my Elky (after I banged the floor pan up a bit).

You couldn't give me another 700 or 200 free. On second thought maybe you could...there's always ebay!

[67ChevyRedneck]

The trick to 700R4's is to get the TV cable adjusted right. You can get a rebuilt 700R4 from Bowtie overdrives for around 800 bucks and it comes with their own "upgrades" to make it stronger. They also sell a TV cable kit and a lock-up kit that works with your brakes (you'll definately need that.) I had a 'yard tranny in mine that blew up after a year. I beat the piss outta it and I now come to find out my TV cable was most likely set up wrong. Truck was a 67 with a 350/700R4/3.73 rear end. I loved it, thought it was a great set-up, fun to drive around town, got 16mpg hwy, and ran about 2300 rmp at 80 mph. Check out bowtie overdrives website for some more good info. Bowtieoverdrives.com

[72MARIO]

Hey Buffalo,

Whoever is building /seting the T.V cables up is doing it totally wrong.

I have a 700R with a 2500 stall stage 2 shift kit behind my mild 355 with posi 3:73 gears. It's the best combo I have ever driven. I only have 1500 miles on it but so far it's awesome.

There is a guy here in town with a 70 LWB 454 .60 over it rund 12's in the 1/4 mile. He has a 700R and it been geting the heck beat out of it for 4 years problem free. he did break couple of cheep stock torque converters but the one in now has been there for 4 years . Mind you this truck is getting beat at the track. So some part has to snap.

[VetteVet]

http://www.transmissioncenter.net/700R4.htm[/URL]

Originally Posted by GloryHound

Sounds like the best way to go is the 700R4. Does anyone know anything about the 4L60E trannies? Are these as good as a 700R4? Anyone know of anybody or place that would trade a Th350 lockup and a Regular TH350 for a 700R4?

The 4l50E is the same as a 700R4 except for some minor differences. Mainly they are computer controlled but they can be adapted to precomputer vehicles. They replaced the 700R4 in 1993. After 1986 the 700R4 was updated and made stronger. There are probably at least a 1000 posts on them in this forum. Do a search in google and you will find more info than you can read on swaps and setups . Here's a website to get you started.


http://www.transmissioncenter.net/700R4.htm

[Gray Ghost]

I know there are isolated incidents of the trannies lasting, but I've never personally witnessed on holding up behind a BB. A buggy of mine trashed his with a 500hp 396 and another buddy just burned his up towing another truck (mild 350 in that one).

You mean the 4L60E? That's the old 700 renamed....it was a much better tranny a few years later. I'd love to have a manual version of the 80E in my Elky.

[cdowns]

[i had a 2004r that had a perforance build, in a 71lwb with 4:11 rear got right at 16-17mpg at 85mph ran that thing fully loaded with car bodies engines and shop tools towing an 8,000 lb trailer fully loaded had no problems with the tranny at all for the 35,000 miles i put on it in a year

[al's71gmc]

I asked the same question a couple of weeks ago. You already got most of the same responses, but here's the link to my thread,
http://67-72chevytrucks.com/vboard/s...80#post1332480 , or if that doesn't work check threads I've started(ther's only one).
After reviewing all the opinions, I've decided to go with the 700r4. Hope this helps, Al