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#1 |
Senior Member
Join Date: Jun 2003
Location: Westminster, CO
Posts: 3,071
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turbo 400 vs 700r..pro's/con's
My 71' SWB driver currently has 3 on the tree. I am collecting all the necessary parts to change over to AT. The engine is a 350 that runs very smooth and is perfect for an everyday driver. Question is do I put a turbo 400 in or a 700r AT??? Can someone that knows AT's tell me what the differences between the two? If it were your truck what would you put in? Just because I'm "old school" I'm leaning towards the th400, but don't want to not consider the 700r if it is the better way to go. Thanks!
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Alex 1971 Lil' Red 350 SBC 700R4 |
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#2 |
Registered User
Join Date: Feb 2001
Location: Ohio
Posts: 1,025
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stock for stock the TH400 is stronger, the TH700r4 has a .76 over drive and also a 3.06 first gear ratio. with a corvette servo and some beefy internals the 700r4 will handle all the power you could throw at it, but the TH400 is bullet proof pretty much.
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#3 |
Registered User
Join Date: Jan 2004
Location: NH
Posts: 2,266
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I have run both transmissions in different conversions, TH400 in a 62 C10 with a 350 and a 67 C10 with a 700r4 with a 350. The OD with normal Standard type rears with gear ratios of 3.73 or lower are almost a must for gas milage, especially on the highway. If you have a modified engine and want to run on the strip the 400 would be a better option. both transmissions are good units the later the better for the 700's because of the initial problems. I have one built buy TCI and have had it for 4years and I will never go back to a 3spd auto and my motor is built up and I am not easy on my vehicles. As fas as instalation goes, they are almost identicle with the exception of bolt holes for cross member and possible driveshaft, I use the standard automatic column shift in my 67. JMO
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#4 |
Formerly yellow72custom
Join Date: May 2001
Location: Austin, TX
Posts: 7,531
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A TH350 would be the cheapest auto tranny option.....a TH400 is much stronger, but the TH350 is fine for a stock or mild engine.
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'72 Chevy C10 Mild 350/TH350/3.07. Ochre/White. Old high school ride. '70 GMC C2500 '62 327 4bbl/SM465/4.56-geared Dana 60. White/White. Project or parts truck. '97 Saturn SL DD. 1.9/5-speed. 40+ highway mpg |
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#5 |
Registered User
Join Date: May 2001
Location: Bethlehem, GA, USA
Posts: 389
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tranny choices
I have run about every GM trans out there with the exception of the newer electronic OD's which I would be drooling at the mouth to have.
I can tell you this. I tried to drive on the power tour last year without an overdrive and it was terrible. Now I have put a 700R4 in mine and it is so much more enjoyable. You can truly have the best of both worlds with the low 1st gear and the overdrive. Just don't go too deep with the rear gears. I haven't taken my 4.30's out of mine yet and 1st gear is about worthless. I have 33" rear tires and even with the 4.30's cruising 80-85 mph is no problem. I am going to swap the rear gear and it will really be awesome. I have a friend with a shop that installs them and even with 3.08's the low 1st gear gives good take off and still cruises on the highway. Unless you are pushing well over 500HP, I would go with the 700. I had to take all the nitrous off of mine because I knew that I would destroy the 700. But to be honest, I did test it a few times and as long as you didn't shift it on the nitrous it still lived just fine. I hit it quite a few times in high gear and it held and pulled like crazy. The only thing that I have found to be a pain in the butt is getting the TV cable adjusted properly. I'm using the Lokar one and if anyone wants to offer me some help with adjusting it, I'm all ears. Sorry for the long winded answer, just wanted to help as much as I could. Tom
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No more dragtruck for me. I'm building a new ride though. It's a '71 fleetside, 400 sbc, 700R4. Working on it now, finally. Soon to have Edelbrock Pro Flo EFI, Vintage Air, 1 piece windows, buddy buckets, etc. My new build thread: http://67-72chevytrucks.com/vboard/s...17#post2861817 Best pass with the old dragtruck: 5.32 @ 131.6 mph 1/8 mile w/ a 1.25 60' Fogger/Plate 2003 Best pass with the street 406 hydraulic roller motor w/ mild plate tuneup 5.93 @ 114 mph 1/8 mile w/ a 1.29 60' 2003 or 2004 Last edited by 67dragtruck; 02-15-2004 at 02:41 PM. |
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#6 |
ran out of money
Join Date: Apr 2003
Location: northern, NJ
Posts: 925
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to be honest with you a 350 can handle any power u want to put in front of it, just the 400 will handle more towing and off-roading better...... the 400 allows the heat to disapate some more then a 350. as for the 700, i just built one for my truck. you can buy upgraded kits for them and now since gm just came out with a 4L65E you can get hardend parts. I would strongly recomend a 700R4 foir anything, i know people running then at the track without problems. they just make sure it doesn't go into 4 gear. The main killer of 700's and most transmissions is heat, make sure you ahve a nice trans cooler on it. people complain about 700's dieing soo quickly and the main causes of it are from heat and improper kick down cable adjustment. Best of luck with your choice.
Rat
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Modify everything, leave nothing alone!~ ![]() ![]() |
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#7 |
My son, my joy.
Join Date: Sep 2003
Location: Spokane WA
Posts: 463
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I have a stock TH400 behind a 327 that came from another vehicle. It's starting to get a bit squishy. If I had the money, I would, for sure, go with the 700r4 just for the overdrive. I just about killed my motor on a 600 mile trip last summer trying to keep up with the rest of the group. 3300 RPM's at 70mph pulling a trailer was not a good thing to do. Also, didn't help that it my motor has an oil leak I've been putting off fixing.
![]() Anyway, if it were me, 700r4 for sure. |
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#8 |
Just Don't Stop!
![]() Join Date: Feb 2004
Location: Dallas
Posts: 1,239
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700r4 are all over ebay for 500-600 plus core charge, not bad!!!
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1968 C10 build in process TT LSA/6L90e/9" |
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#9 |
Beer Power!!!!!!!!!!
Join Date: Nov 2003
Location: Nacogdoches, TX
Posts: 280
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My bro had a stock 700r4 in a deisel 85 Blazer. Took out the deisel and put in a 454 out of an RV. Motor was probably around 400 hp but was a TORQUE MONSTER. He destryed the tranny in 2 weeks, so, instead of getting the 400 out of the RV, he lets a street/strip tranny shop in Shreveport talk him into a Corvette stylr setup for his 700r4. Wouldn't you know it, 1 month later he blows the damn thing again (along with 2 rear ends). Shop refused to help him since it was past the 30 day warranty. A lot of bucks down the tube!
I love this story- we used to get in that Blazer and walk Z-28 Cameros in a full size blazer. He would put it in 4 wheel drive and white smoke all 4 33" Super Swampers!! HAHAHA Just had to share this-wish I had pics!
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Rather be fishin' |
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#10 |
Registered User
Join Date: Jan 2004
Location: NH
Posts: 2,266
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67 dragtruck have you gotten the proper hardware from Edelbrock for this MPFI, I know Holley released a proper cable setup later on to fix the same problem, This is another reason why I am going to the stealram, Stock TPI brackets work with the stock TV Cable.
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#11 |
Registered User
Join Date: Dec 2003
Location: Left Coast
Posts: 254
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67 Drag Truck
You might want to check out www.700r4.com. They seem to have the TV cables problems worked out
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Toys: 72 K5 Blazer 74 Vette |
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#12 |
Semper Fidelis
Join Date: Dec 2001
Location: Cedar City, Utah
Posts: 654
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Me being a cheap skate I would put in a 350, you would never know if you had a 400 or a 350 when you are driving. If I had money and or no kids in the house I would put in the 700.
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72 Chevy C 20 with 402 For sale 85 GMC K2500 ![]() 83 Trans Am Cedar City, Utah (Missouri Native) |
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#13 |
Registered User
Join Date: Jan 2003
Location: Seattle WA
Posts: 1,466
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In my opinion the difference is strictly money.
It won't cost that much for a bullet proof T400 that will take a serious beating. However to get 700R4 in that range. it's gonna cost you some more cash. However you get overdrive. It really depends on the motor and what you will be doing with the truck.
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FocuzTech Performance Evergreen Protective Coatings Gatorhyde...the best kept secret in spray in bed lining & protection |
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#14 |
Just Don't Stop!
![]() Join Date: Feb 2004
Location: Dallas
Posts: 1,239
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Daily driver with less than 350 hp go with the 700r4 I say!
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1968 C10 build in process TT LSA/6L90e/9" |
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#15 |
Registered User
Join Date: Jan 2004
Location: Arizona
Posts: 157
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Love my 700R4. I am getting 15 mpg in my 72 carbureted Burb. It has paid for itself already in saved gas money.
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72 C10 Burb 350 700R4 70 C20 LWB 350 Crate TH400 68 Chevelle |
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#16 | |
Registered User
Join Date: May 2001
Location: Bethlehem, GA, USA
Posts: 389
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brackets
Quote:
Tom
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No more dragtruck for me. I'm building a new ride though. It's a '71 fleetside, 400 sbc, 700R4. Working on it now, finally. Soon to have Edelbrock Pro Flo EFI, Vintage Air, 1 piece windows, buddy buckets, etc. My new build thread: http://67-72chevytrucks.com/vboard/s...17#post2861817 Best pass with the old dragtruck: 5.32 @ 131.6 mph 1/8 mile w/ a 1.25 60' Fogger/Plate 2003 Best pass with the street 406 hydraulic roller motor w/ mild plate tuneup 5.93 @ 114 mph 1/8 mile w/ a 1.29 60' 2003 or 2004 |
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