700r4 or T-56

[twillie2460]

68 sw with vortec, 350 trans and I belieive 4:11's wanting to drop highway rmps down. Already have the the 700r4 trans and aftermarket crossmember to fit the truck. It has been years since I ran a 700r4, in was in a 85 surburban but did not have much luck with many trans I put in that truck. Had the truck 4 years and put in 5 trans but thought the newer ones were much bette,r but after talking with some people I am having second thoughts and now really considering scraping the 700r4 project and going to t T-56. Already have one found from a 95 LT1 Camaro with 31,000 for 1000 bucks and just looking for thoughts good or bad I guess.

[Tx Firefighter]

I really like 700R4 transmissions myself. You have to make sure it is upgraded properly though. Lots of the stock rebuilds don't live long. I use Phoenix Transmission to build mine. They aren't cheap, you're looking at a good bit of money for a rebuild, but they are warrantied for up to 550 horsepower and 3 years. I've never needed the warranty though as they have always worked right. They're the same folks that built all of Boyd Coddington's transmissions. Look for their add in most magazines.

http://www.phoenixtrans.com/html/gmtrans.html

[Jim_PA]

Do you like driving? Or do you just like pushing the gas pedal?

[twillie2460]

Originally Posted by Jim_PA

Do you like driving? Or do you just like pushing the gas pedal?

Well not sure I truley understand what you are asking. I would like to drive and drop rmp down a bit as i run 3k at about 60 to 62 or so not sure as speedo not working.

[capev86]

what he means is.....a manual trans is good in a driver's car (those who are into sportiness and being in control of everything) and an auto is good for commuting, cruising or towing (torque multiplication).

the 700-r4 has a great overdrive ratio and is a good trans overall if in good condition and not abused or if you have it built up. the locking converter helps even more. i say run synthetic atf and an aux cooler....all autos run hot. my dad had the 700 in his 84 burb. it was an early one and had been rebuilt by 100,000 miles. we put a 406sbc in front of it and hauled our 71 holiday camper (all 6,000 pounds of it) out to yellowstone and back on a month long trip. the trans never missed a beat. its all about the few people with bad luck being the ones that start the name calling......just think of the bad rap that the quadra jet gets.

if you want even better highway smoothness, some manual transmissions have an even better top ratios than the 700 and a can also have a really steep first gear which is great for towing 'cause you don't get the torque multiplication from a torque converter. i read some gear ratios charts in my new summit catalog.....heck yes!!!

[allthrottle,nobottle]

700r4 will be better at drag racing while t-56 will be more fun to drive IMHO

[twillie2460]

Originally Posted by allthrottle,nobottle

700r4 will be better at drag racing while t-56 will be more fun to drive IMHO

I do not plan and drag racing it it just what I am replacing my 200,000 mile truck with. I could had spent the money on a new one or make a old one like a new one and I liked that plan much better, plus imho they look better too.

[Tx Firefighter]

He is implying that having anything less than three pedals is not driving. Just blow it off.

[twillie2460]

Originally Posted by Tx Firefighter

He is implying that having anything less than three pedals is not driving. Just blow it off.

I understand that as my older brother just told me about the same thing not even 30 minutes ago.

[Jim_PA]

Originally Posted by Tx Firefighter

He is implying that having anything less than three pedals is not driving. Just blow it off.

Pretty much so, but I do realize that enjoying the full driving experience isn't for everyone.

[twillie2460]

This t-56 was already in a 67 c-10 and the trans tunnel did not have to be modified to accomidate for the size of it which is good. I now have to decide to go with a manual or auto. I am really leaning towards the t-56 but it will cost alot more $ to complete that setup. I will most likely dump the bench seat and go to buckets and a console perhaps. One good thing is I also wanted swap out steering colums to a IDIDIT and that one is alot cheaper than one with a shifter in it.

[Jblackie47803]

I have never felt comfortable with 700r4's from a durability outlook. I'm sure if you throw enough money at one it will last a while, but nobody I know has ever had much luck with them. Just my $.02

[Ackattack]

keep in mind also that the t-56 has 2 overdrive gears. 6th is a 50% OD, so your cruising RPM at 60 would be about 1500.

Depending on the torque of your engine, this may make the truck feel real sluggish and may have to shift to 5th going up hills. In my corvette and trans ams they'd cruise at ~1400 RPMs @ 60 and it was fine, but the fuel injected engines are set up for this.

When I put a 700R4 in my 72 I had 3.08 gears and it cruised at ~1600 RPMs and it felt sluggish also. I swapped to 3.73s and it was great.

Just some things to keep in mind.

[twillie2460]

Originally Posted by Ackattack

keep in mind also that the t-56 has 2 overdrive gears. 6th is a 50% OD, so your cruising RPM at 60 would be about 1500.

Depending on the torque of your engine, this may make the truck feel real sluggish and may have to shift to 5th going up hills. In my corvette and trans ams they'd cruise at ~1400 RPMs @ 60 and it was fine, but the fuel injected engines are set up for this.

When I put a 700R4 in my 72 I had 3.08 gears and it cruised at ~1600 RPMs and it felt sluggish also. I swapped to 3.73s and it was great.

Just some things to keep in mind.

I have not looked real close at my rearend yet but from what I have calculated I think I have 4:11's and if it is not that it would have to be 3:73's
as it is to low geared for it be anything else.

[dmnall]

Originally Posted by Ackattack

keep in mind also that the t-56 has 2 overdrive gears. 6th is a 50% OD, so your cruising RPM at 60 would be about 1500.

Just some things to keep in mind.

Well actually depends on which model of the T56 you get because the 97 - 2004 C5 *non Z06* and 98 - 2002 F-Bodys *ls1 based* had that gearing. However, the C5 Z06, C6, Pontiac GTO and other cars have 5th 0.84 and 6th 0.56 except gto was 5th .80 and 6th 0.62 because these trans were built more aggressive and in stock form the GTO Trans is a little stronger compared the ls1 F-body trans when comparing stock to stock because the shift forks were stronger as well as no more plastic syncros...

HTH,
Charlie

[Ackattack]

Originally Posted by dmnall

Well actually depends on which model of the T56 you get because the 97 - 2004 C5 *non Z06* and 98 - 2002 F-Bodys *ls1 based* had that gearing. However, the C5 Z06, C6, Pontiac GTO and other cars have 5th 0.84 and 6th 0.56 except gto was 5th .80 and 6th 0.62 because these trans were built more aggressive and in stock form the GTO Trans is a little stronger compared the ls1 F-body trans when comparing stock to stock because the shift forks were stronger as well as no more plastic syncros...

HTH,
Charlie

yeah, but he said it was a 95 LT1 T-56. which I believe would have a .50 6th gear. I believe there was an LT1 T-56 tranny that had a higher 6th gear but if I remember right, that was a 93 only option.

[Crispyr1]

I just changed my tranny out not even a month ago from the 3 speed to the 700 and I also have the 4:11's in the rear and I can't even tell you how pleased I am with the change! I'm not pushing a lot of power with it so i'm hoping/ expecting it to last me a long time! The 4:11's just required to much shifting!!!!

[CB24]

The thing that turned me off of the t-56 is that the shifter comes back so far that you have to lose the bench seat.

[twillie2460]

There is a kit that moves the shifter to the middle of the trans

[CB24]

Originally Posted by twillie2460

There is a kit that moves the shifter to the middle of the trans

Really? Cool I didn't know that. When I get to that part of the buid I know what I'm going to run now!

[twillie2460]

Originally Posted by CB24

Really? Cool I didn't know that. When I get to that part of the buid I know what I'm going to run now!

http://www.keislerauto.com/gm/gm-bar...page_tabs.html
above is just one that I found already not really cheap though as it is 300 bucks.

[Jim_PA]

TooTYpo many gears is better than not enough!

[twillie2460]

Picked up my T-56 yesterday I am getting just a little excited about this next upgrade. I also got to play dress up today I will post a some pics soon of the progress so far. I sure like polished aluminum. I sure really was not thinking right, the guy that sold be the t-56 also had tubular controls are upper and lower right and left side with ball joints $200 a few hours later he told me if had made the over of 200 I could had the controls too but he had told me they where supposed to be taken the next day. I did not want to step on toes but later thought I should had stomp on this deal.

[twillie2460]

Originally Posted by twillie2460

Picked up my T-56 yesterday I am getting just a little excited about this next upgrade. I also got to play dress up today I will post a some pics soon of the progress so far. I sure like polished aluminum. I sure really was not thinking right, the guy that sold be the t-56 also had tubular controls are upper and lower right and left side with ball joints $200 a few hours later he told me if had made the over of 200 I could had the controls too but he had told me they where supposed to be taken the next day. I did not want to step on toes but later thought I should had stomp on this deal.

having a hard time finding where you upload pics can any tell me where to load pics of trucks progrees or do I have to use offsite storage and point url to that spot.

[-T-]

Im also in the middle of a T56 swap behind my 6.0 FI, and I did have to cut my tunnel and get a high hump cover. It barely hits though, so I think that if you motor sits just a half inch or so lower that it will clear fine. I just went ahead and did mine instead of trying to lower the motor. I think though that the LT1 trans are slightly different from the LS1's so that may be the difference as well.

As for the pics, when you are in the "Reply to thread" screen, scroll to the bottom and you will see 'manage attachments', click on that and browse through your pics on the computer and attach them.

Good luck with your swap... im down to plumbing the hydraulics now and should have it wrapped up shortly...if i can help any, feel free to ask.