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TH350 vs. TH400 vs. 700R4

Discussion in 'The Hokey Ass Message Board' started by blown240, Aug 7, 2010.

  1. blown240
    Joined: Aug 2, 2005
    Posts: 1,651

    from So-cal

    I am buying a new tranny and I need to figure out which if these would be my best bet.

    This is what I have:

    88 350 Chevy, converted to carb. Probably makes about 280 hp. Rear end is either a 2:73 or a 3:23, I pick it up next saturday. This is all going in my 51 Chevy. The car is a total cruiser, but a little off the line grunt would be fun.

    So I need to figure out which of these trannys would suite me best. I can get them all from a local rebuilder for the same price and with the same warranty. The 700r4 has the OD gear which is nice, but I think the case is bigger, and I am not sure if it will fit the tunnel. I know the th350 will fit, but its only a 3 speed.

    Last edited: Aug 7, 2010
  2. nutajunka
    Joined: Jan 24, 2007
    Posts: 1,466

    from North Indy

    700R4 lower first gear for take off and overdrive while on the hwy. Trans. humps aren't hard to enlarge.
  3. Deuce Roadster
    Joined: Sep 8, 2002
    Posts: 9,520

    Deuce Roadster
    Member Emeritus

    The 350 will fit places the other have difficulty fitting ( size ). It is also the most forgiving in setting up. IT is a 3 speed :eek:

    But when your gear ... it will be OK ...

    The 700R4 has a low first gear ... ( 3.06 ) so your Chevy would have more low speed takeoff. The 350 has a 2.52 first gear. NOTICEABLE difference.

    It is sort of like deciding ... you like a BLONDE, A REDHEAD or a BRUNETTE ??

    I prefer brunettes myself.
    I used a 700R4 in my last project ... and will use one in my next project also.

  4. zzford
    Joined: May 5, 2005
    Posts: 1,822


    The 700r4 is the only way to go. I put one in my coupe and it is one of the best things that I did to the car. 355 HP ZZ4 chevy with 3.50 gears and it'll pull a solid 20 mpg on the road.
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  5. 57JoeFoMoPar
    Joined: Sep 14, 2004
    Posts: 4,332


    I don't look at it quite the same way. The 700R4 is like having the blonde, AND the brunette.
    You're getting the extra jump out of the hole with the lower gear in first, and you're getting the extra juice down the highway with the OD. Better acceleration, better milage, higher cruising speed, less wear on the engine.... Hell, you're getting the redhead too!
  6. InPrimer
    Joined: Mar 10, 2003
    Posts: 778


    Have a 350 in for 15 yrs, next project,700r.
  7. there anything inherently bad about using a T400? I'm at that point where I could switch to a 700R4 or a built up 200r4, but would I have to move the rear mount and change the driveshaft length if I used the 700R? and what would I do about the electrical hookup to the tranny? the lesser the better would be great for me. I have a similar set up 350 sbc in a highboy coupe with 3.00 9" rear, as mine is being set up as a highway car and that overdrive sure sounds good to my ears...
  8. Scarebird
    Joined: Sep 26, 2006
    Posts: 852

    Alliance Vendor
    from ABQ, USA

    You forgot the TH200-4R. According to the big trans guys they are actually stronger than the 700; smaller, lighter, and a better 1st gear ratio. I have had a mildly built 200-4R behind a 462 in a 4000# car for over 10 years with no issues.
  9. Deyomatic
    Joined: Apr 17, 2002
    Posts: 3,095

    from CT

    Figure out the exact rear end ratio and post up your tire height, too. It makes a difference.

    If you actually DO have 2.73s, then I'm for the TH350...tough as nails..well, tough enough for your 350 anyway and so much less BS to worry about. I had one behind a 350 with 205K on the clock. I got it with 92,000 and in all that time all I did was change the fluid regularly and the modulator once. With 27.5" tires, it would cruise nicely on the highway at 75 at around 2500. With 3.23s that goes up to 3000.

    Now, I also had a different car with 2.73s and a 700R4. USELESS. Sure, first gear was nice, but by the time you wanted it in OD, you were only spinning around 1500 RPMs and if you came to any kind of an incline it would need to downshift. I found myself driving in third most of the time, even on the highway.

    Now, for the 700R4 BS part...Sure, it's fairly easy to set up the TV cable, but all you have to do is MENTION 700R4 to anyone and they always say, "Make sure you set that TV cable up right or you'll fry it in a matter of minutes." If you're on the OCD side, like me, this will be in the back of your mind EVERY TIME you drive it. I'm running one right now and every noise that I hear I assume the damn thing is about to blow up, but I've got 3.73s so it's nice to know that OD is there.

    I have zero experience with the TH400, but from what I gather it's about as badass an auto tranny that you can get. It's probably overkill for that mild 350 you have.
  10. need louvers ?
    Joined: Nov 20, 2008
    Posts: 12,912

    need louvers ?

    You would have to be nuts in my opinion to live in So-Cal with every trip being freeway travel to build a car WITHOUT an overdrive! You will have to gear the rear end properly, but man when you do, it's nothing but positives! Oh, and I vote for the 200R4 too. Allot more compact and a bit more efficient.
  11. blown240
    Joined: Aug 2, 2005
    Posts: 1,651

    from So-cal

    The 200r4 isnt an option. The place I am getting the tranny from wants more for a 200 than a 4L80.
  12. If the same price, who wouldn't go for a deeper 3.06 first gear and OD to boot. I think the TH400 first gear is 2.48 not 2.52 FWIW. I have a TH350 in my Mercury and that might change.
  13. xlr8
    Joined: Jun 26, 2006
    Posts: 651

    from Idaho

    TH 400's take alot of power to run, I've seen figures as high as 40 HP, that's their only drawback. The previously mentioned low first and overdrive are certainly nice on the 700's, HOWEVER...........when they fail (not if), they are the most frustrating POS ever put on the face of the earth. IF you get a well built one you will enjoy it for years, if you get a lemon or one with some mismatched components which is very common now because there are so many variations, you will curse the things for the rest of your life. I'm currently at the point of hating the damn things after several very bad experiences.
  14. If you have 2.73's run the TH350
    If you have 3.73's run the 700R4

    If you have 3.73's and want a better trans, spend the dough for a 2004R.

    I have 2.97's and a TH400. It loves the highway speeds. It's still fun around town even with a 2bbl. I wish it had a TH350 to free up some needed power though.

    The TH400 and 2004R are nearly the same size, so they will interchange without modification to the trans crossmember/mount. I plan to run a 2004R with some 3.73's in the future, unless I get a wild hair and decide on a T5.
  15. Lowmerc50
    Joined: Apr 25, 2008
    Posts: 588


    No choice 700 R!!!!!!! The only way to go..
  16. [​IMG]

    Trans 1st Gear 2nd Gear 3rd Gear 4th Gear Reverse
    Powerglide 1.76/1.82 1.00 --- --- 1.76/1.82
    TH350 2.52 1.52 1.00 --- 1.94
    TH400 2.48 1.48 1.00 --- 2.07
    TH200-4R 2.74 1.57 1.00 0.67 2.06
    TH700-R4 3.06 1.62 1.00 0.70 2.29
    4L80E 2.43 1.49 1.00 0.75 2.07
  17. aaggie
    Joined: Nov 21, 2009
    Posts: 2,529


    Shop around for other prices on the 200R you might find one for less. Otherwise I vote for the 700R4. I run a TH350 behind a 4.3Vortec in my '37 Terraplane with 3.50:1 gears and it works great. I have a 700R4 in my '40 Chevy behind a strong 350SBC with 355:1 gears and it is a great cruiser.

    Bowler and TCI sel la kit for the TV cable that makes the adjustment bulletproof and automatic.
  18. Satinblack
    Joined: Jan 1, 2004
    Posts: 970


    I agree, depends on the rearend, I ran 2.73 in my panel with a big block chevy and 350 trans, did great on gas.

    The impala im building will be 383 stroker with a 400 trans and 2.73 out back

    400 tough as nails, besides that i build them myself and con do it in my sleep :)

    if your running low gear rear then 700 or 200
  19. blown240
    Joined: Aug 2, 2005
    Posts: 1,651

    from So-cal

    Well I guess first I need to find the exact rear end ratio.

    The tires on the car are L78-15. I think they are 29.3" tall. I do have some G78-15s and some 6.50-15s, but I really like the L78-15.
    Last edited: Aug 7, 2010
  20. kyhotrod
    Joined: Oct 25, 2006
    Posts: 125

    from Kentucky

    It's hard to beat a TH350 with a good highway gear, but I'm very satisfied with my 200R4 from GearStar, running 3.73 out back. 4 years no problems whatsoever.
    Joined: Apr 7, 2007
    Posts: 714


    I always take the one with the big TITS.
  22. This graph doesnt show how the x member mount on the 200R, is almost all the way to the end of the case.(from the front of the bellhousing, to the cross member mnt, it's longer than the 700R4) 200R4 case is all one piece, no seperate tailshaft housing. An X Frame, or convertible type X crossmember in the middle of the frame, makes things tight.

    700R4, all the way.. BUT, Do Not drive around town in fourth gear! OD for long jaunts and hwy use only. It'll last like mine has for 16yrs.
  23. blown240
    Joined: Aug 2, 2005
    Posts: 1,651

    from So-cal

    What about lockup converters. Does the 7000r4 have to have one? Also, with out a lockup, is there any electrical connections for any of these transmissions.
  24. J.Fishbeck... See the little oval in the bottom corner of the diagram that says "Transmission Mount"... each trans in the diagram shows the mount and centerline location of the mount. 2004R being 27-15/16" from the bellhousing edge to the trans mount bolts which matches the 2004R I have in my '53 Chevy, as well as the TH400 that I have in my '56 F100.

    blown240...the 2004R and 700R4 need a lockup switch. Use one from Rebel Wire, it's the simplest and best one out there, it's also cheaper than the other complicated lockup kits and it's HAMBer made. Kits

  25. First of all, I don't think the trans case will come anywhere near the tunnel, if you mount everything normally.

    What ever the rear end ratio is, you should use the OD trans.

    I had a Caprice, 305 TBI, 700R4 that came from the factory with 2.56's ,in a 4000 lb. car. That's an effective 1.79 ratio in OD. It was completely stock and over 100, 000 miles, and it would pull up most interstate grades in 4th lockup, cruise on, 70 mph. Got 28 mpg like that. (of course it only got 14 around town).
    You said you are building a cruiser, so cruise it in OD and save some gas.
    If you are going to use a stock type or very mild camshaft, I'd lock the converter up too. That'll drop the R's 3-400 more.
  26. Scarebird
    Joined: Sep 26, 2006
    Posts: 852

    Alliance Vendor
    from ABQ, USA

    That works fine - for a fuel injected motor. My old 83 Camaro had a 700R4 with Tuned Port 305 (later 350) with 2.73's (later (3.23's) that would cruise the freeway at 1700 rpm. My Lemans with 3.23's and a 462 was another story - It hated running around 1600 at freeway speed, switching to 3.55's made all the difference.

    The lockup needs no special kit - one wire runs the OD lockup, another drive. I currently have mine set up to lock in OD only, but that will change when I install the 440 (0.060 over 400 w/4" stroker crank).
  27. hemiboy
    Joined: Apr 21, 2005
    Posts: 248


    I've used them all. I just switched from a turbo 400 to a 700R4 in my '34 chev with a 327. I didn't change the gears, they're 3.25s. The only problem is that I have to lock out 4th until I'm at 70, or the engine only runs about 1400 rpm, which is a little low for my engine. It's definently quicker off the line! Yes, I'd do it again!
  28. 40hemicpe
    Joined: May 12, 2007
    Posts: 959


    i had a lockup th350 in my old 53 chevy . was great trans :D
  29. Lucky3
    Joined: Dec 9, 2009
    Posts: 652


    X2 - 700r4
  30. blown240
    Joined: Aug 2, 2005
    Posts: 1,651

    from So-cal

    So other than the converter are there any electrical hookups on either of these trannys?

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