Trans Decision

Discussion in ''Da Nailhead' started by Wicked50, Mar 6, 2010.

  1. Wicked50

    Wicked50 Well-Known Member

    I just picked up a SP400 for my truck. I should have it on the road soon.
     
  2. DaWildcat

    DaWildcat Platinum Level Contributor

    Keep us posted!

    Devon
     
  3. 66larkgs

    66larkgs paul 66gs turbo nailhead

    why are you close to only buick transmissions? are they the only ones that are available to you for real cheap and tring to keep it on the cheap? i spent about $1000 into my th400 for my nailhead. i got rid of the s/p and put a 1900 stall in it because of the setup with the turbo. If you plan on building a nice driver and not be afraid to take it on the long haul or a nice highway cruise and get gd fuel milage ,look at some other transmissions.From exsperience i would look at one with overdrive. The 700r4 has a great first gear that would get you out of the hole like a bad ass and they have overdrive so @ 65mph you are at 1900 - 2200 depending on rear gear and tire.They are a dime a dozen and cheap to buy. I have use a 700r4 in a jeep i built that was a monster with 38's and 3:73. They do have their weaknes but thier are a easy fix when rebuilding. the 200r4 is a gd transmission and of corse the th350 th400 but those two dont have od. You can buy the kit to change from a nailhead bellhousing to a chevy was said to be around $400. A nice used 700r4 is $200 and a 200r4 is $200 $500. I would have your transmission pickout before your rear gear. Have your tire and wheels pickout before your rear gear. Are you building this truck back to stock or hot rodding it out? s 10 chassis are real easy to put under that truck and you would have updated chassis, wireing, and steering. find a old 2 wheel drive s10 remove the body and the 4.3 keep the 700r4 and throw in the nailhead. I have pictures from start to finish minus the nailhead. with my s10 chassis swap in my 53. just a thougt:TU:
    Paul
    66 gs 401 turbo
    53 chop top international
     
  4. John Codman

    John Codman Platinum Level Contributor

    I'm taking a break from doing my income taxes on this very rainy Sunday afternoon, and just had to stick my two cents worth in here. I originally was going to use a THM 400 in my nailhead-powered Chevy pickup. I even had it rebuilt and bought a new converter for it. After doing some serious thinking, and asking for opinions from a number of people whom I trust and respect, I changed my mind and bought a street 700R4 from Raptor down in Louisiana. I got an adapter from Brendtsens', and the setup works great. In this day and age, you really need an overdrive unless you are going to run a 2.73 or taller rear axle ratio. IMHO the low first gear ratio in the 700R4 is lower then a nailhead needs unless you are going to race it, but I will put up with it in order to have the overdrive. 20 mpg on the highway in a carbureted 4,465 lb pickup truck with 431 cubic inches ain't bad. Think about it.
     
    Last edited: Mar 14, 2010
  5. nailheadnut

    nailheadnut Riviera addict

    John,

    Good choice.

    Here's some other information about o/d swaps for others who might be considering something similar.

    That tall 3.06 first gear in the 700-r4 is one of the reasons why Dave and I chose to go with the 200-4r. Besides the closer spacing of the gears, which keeps the nailhead in the power band of its torque curve, the 200-4r has an even lower overdrive gear than the 700-r4. Both transmissions can be built to take the hp and torque of the nailhead so there's really no discussion about which one is "tougher." The other, bigger, factor that Dave and I had to consider was the overall size of the unit. For all of you who might be contemplating this swap with cars having an X frame like the Rivieras', there's not enough room to run the 700-r4 without doing some frame mods. There's something inherent to the 700-4r that doesn't apply to the 200-r4. The 700-r4 will not shift into o/d at WOT, this is probably only important if you're an all out racer.

    I'll be running the 3.91 gear set that I have with the lower 2.78 1st gear of the 200-4r. That would be the same as you running a 3.55 gear with the 700-r4. The final drive of a 200-4r with a .67 overdrive and the 3.91 gear set will be a comfortable cruising gear of 2.62. The final drive in a car equipped with a 700-r4 and 3.55 gears will be 2.48. Both are livable and will add great flexability to the vehicles they're in. If you run anything much lower than 3.50 gears, you'll really lug your engine down. I've calculated that with my set up and 27.5" diameter tires, that I'll be turning the engine at about 2150 rpms at 70 mph.

    After that is all set up and working correctly, my plans are to put a complete 8.8" Ford rear end out of an Explorer under the Riv. That rear end comes with 3.73 gears, posi, and rear discs. They're the right width, inexpensive, plentiful, and tough. If you think about it, a 12 Bolt GM actually has a smaller ring diameter.

    Make sure you get the TV cable hooked up to the carbretor and adjust it properly before you ever put the car on the road. You'll fry that new transmission before you can get to the end of your block if you don't. Did Raptor supply you with an external 12V unit of some kind to controll the converter lock-up?

    Good luck and keep us posted with picture updates.

    Ed
     
  6. r0ckstarr

    r0ckstarr Well-Known Member

    Going back a few posts in this thread. In View B, the switch closes when you take your foot off of the throttle.

    On my car, the bushings on the throttle rod (next to the identification hole) were worn and sloppy. Because of this, no matter how you adjusted the switch, it still would not close. I could not find new bushings at the time, and needed to get everything functioning.

    I made a bracket that bolts to an existing threaded hole in the intake manifold. This bracket holds this switch right under the flat part of the carb linkage where the diagram shows the Dash Pot. When I let off of the gas, the linkage closes and also closes the switch. I set it up so that if it ever needs adjustment, I just loosen the bolt holding the bracket, adjust, and retighten. It's worked so well that I never looked into putting it back where it's supposed to go.

    I don't know how the throttle rod is in the truck he's using. Just thought I would add this in, just in case he doesn't have anywhere to mount his switch.
    --------

    Now the funny thing. Until this thead, I didn't know that is where the Dash Pot went. Mine was missing from my car when I got it. Now I know what existing hole i used for my bracket, lol.

    (I was told that the Dash Pot just keeps the car from dying due to a sudden deceleration. Sort of like a cushion to keep the throttle from slapping closed too soon. I've never had a problem with it dying, so I still don't have one. )
     
  7. Wicked50

    Wicked50 Well-Known Member

    Did I pick the wrong trans. I am using the truck just to cruise around town and light them up every once in a while.
     
  8. John Codman

    John Codman Platinum Level Contributor

    Here's a shot of the throttle and kickdown/shift cable on my pickup. I don't remember whether this was before or after it was adjusted. It works great. Some of the bits and pieces are storebought and some are homemade.
     

    Attached Files:

  9. nekkidhillbilly

    nekkidhillbilly jeffreyrigged youtube channel owner

    no comment here from me but if you want to take that stang um yeah difference between 14s and 12s with it
     
  10. nailheadnut

    nailheadnut Riviera addict

    You're fine with the trans you picked. The ONLY reason you'd want either of the o/d transmissions is for longer highway trips where you'd be able to cut down on engine speed for long periods at a time and perhaps drive it far enoungh so the savings in fuel will pay for the o/d swap.

    Don't second guess yourself everytime someone talks about something different or something they've done. Stick by what you've got and fine tune it.

    You'd be surprised at the number of guys running four speed transmissions who'll barely get the car into 4th gear by the end of the track. Waste of transmission and gears if the cars not screaming in 4th at the end of the 1/4 mile.

    Ed
     
  11. nekkidhillbilly

    nekkidhillbilly jeffreyrigged youtube channel owner

    i disagree w/ you could gear it with a 2004r or 700r4 car extremeley low in the rear end and still have the top end gears on top of it not to mention the lower first gear and closer gear spacing . this will extremley help your hole shot.

    the trans he has is fine for a weekend cruiser though but i think hed see a big increase with the od trans

    i wouldnt change it now but initally i would have went od and not looked back
     
  12. CameoInvicta

    CameoInvicta Well-Known Member

    Yea, but with the money you have in an OD trans and adapters vs. a ST400, adapter, flexplate, and starter, you could easily put what you saved into the motor (cam, head work, etc) and see more gains. I don't think a 200R4 or 700R4 would be worth 50 or more horspower.

    I'm perfectly content with my ST400, and I plan on doing a little racing this summer.
     
  13. 64Electra

    64Electra Alex BCA# 44430


    Have you even driven your car since you put in the ST400??????
     
  14. CameoInvicta

    CameoInvicta Well-Known Member

    Nope, still working out the kinks of the swap and still need to get the driveshaft shortened. Plus, it's still winter here in MN, although it has been VERY warm the last week or so.
     
  15. nekkidhillbilly

    nekkidhillbilly jeffreyrigged youtube channel owner

    well that depends too i have 50 bucks in a gn 2004r and the adapter is 400 and now you dont have to replace the starter or flexplate for the new adapters so it would be just as cost effective really. like i said i wouldnt replace it but i would be my first choice if i was needing a trans.
     
  16. CameoInvicta

    CameoInvicta Well-Known Member

    I think you got a pretty good deal on the 200R4. Which adapter do you have? I know Bendtsen's is closer to $800, and I thought Marty's was more than $400. You would still need a flexplate, not sure on the starter though.

    I think both are good choices, it just depends on whether you need need OD or not. In my opinion, I'd rather have a ST400 with a gear vendors setup. That would be slick :cool: .
     
  17. nailheadnut

    nailheadnut Riviera addict

    Andy,

    If you'd do some research or read some of the threads that Marty has posted, you'd know exactly what each kit consists of.

    Is this week spring break for you and if so, are you getting anything done on your car?
     
  18. CameoInvicta

    CameoInvicta Well-Known Member

    Sorry Ed, I'll be sure and look up every little fact before posting next time.

    Nope, spring break is the week of the 29th for us. I'm heading to Florida - it's warm here but it's warmer there :cool: . I'm getting stuff done on the car, in fact I worked on it for a few hours today, along with doing some yard work. I got my intake all painted up, and starting mocking up the Hurst shifter. It's coming together, albeit not as fast ad I'd like. It's hard to find time between school, working, and all the misc stuff I've got to get done around the house.
     
  19. DaWildcat

    DaWildcat Platinum Level Contributor

    Guys, you've pretty effectively trashed Wicked50's thread.

    How about getting back on topic?

    Devon
     
  20. nekkidhillbilly

    nekkidhillbilly jeffreyrigged youtube channel owner

    im buying martys and his can work with the dynaflow flexplate also he has both options. its like 450-500 depending on which model. yeah the st400 with gearvendors would be sweet expensive though. could you imagine a gv with the 200 that may be over kill but you could run 456 gears and still cruise at 2k
     

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