Finding the 430 a mate

Discussion in 'The "Juice Box"' started by Nailhead Ronnie, Nov 22, 2017.

  1. Nailhead Ronnie

    Nailhead Ronnie Well-Known Member

    Will a Buick 430 inside of a 65 Skylark be more happier performance-wise with a 200r4, 700 R4, or switch pitch th400. Want to be real fast off the line and be able to be in the freeway going 80 like nothing.

    There's a couple 88 Corvettes in my junk yard. Are v6 700r4 Obsolete and should i only be looking for V8 700 and 200( did Buick even have a V8 to go with the 200r4, wasn't the best one in the Grand National?
  2. TrunkMonkey

    TrunkMonkey Well-Known Member


    It has wider gear ratios than the 700R4, and Buicks like wider better than close ratio.

    The SP ST400 might be fun, but you will miss the overdrive at 80MPH.
    What rear gearing do you have?
    Nailhead Ronnie likes this.
  3. Nailhead Ronnie

    Nailhead Ronnie Well-Known Member

    Ok thanks. I never knew the buick s preferred a wide ratios, must be because all the torque right? I'll focus in on the 200r4 now. I remember reading the 87/88 Cadillac Fleetwood Brougham had the desirable transmission? What's typically done to a 200r4 to make it stronger?
  4. Nailhead Ronnie

    Nailhead Ronnie Well-Known Member

    I believe my car was a odd fire v6 car, I got it with no engine, so I don't know the rear gear ratio.
  5. TrunkMonkey

    TrunkMonkey Well-Known Member

    Yes, Buicks typically have a flat and broad torque curve, and close ratio just takes away from that benefit.

    "Other" engines are "peaky" on the horsepower and often higher RPM, and the close ratio gears keep the engine in that area better.

    But, rear gearing has a lot to do with what works well.

    You likely have 3.23 gears if it were the 3 or 4 speed , and 3.08 for the ST300 The V6 would need that to move it.

    3.08 will be a hot ticket for the 430 and a 200R4.

    I had 3.08 in a 64 Special with a pretty radical small block, and it was a hoot to drive.
    Nailhead Ronnie likes this.
  6. Nailhead Ronnie

    Nailhead Ronnie Well-Known Member

    Thanks for the tip about the rear gear i should be using?. What kind of diferential should I swap in? Im thinking the stock one won't be strong enough?
  7. TrunkMonkey

    TrunkMonkey Well-Known Member

    The stock one should be fine, if the 430 is stock or mild performance.

    The '65 GS used the same rear end as the Skylark/Special, but they used the convertible boxed frame, beefed up the suspension, steering links and torsion links, but the rear was the same.

    That was behind the 401 Nailhead and putting put similar torque and HP as the 430 later had, so you should be fine.

    If there is no tag on the rear end, lift the rear wheels, block the front tires, put it in neutral and spin one of the wheels forward as if it were driving the car forward, if the other wheel turns opposite, you have an open differential, if the other wheel turns the same direction or does not move, it is posi. (almost 100% certain).

    Posi will be fine, open you may find it spinning the tire quite a bit when you romp on it.

    Once you know, post back, and folks can discuss options and recommendations.

    Don't throw money as a solution looking for a problem to solve.

    Sometimes you are already ahead of the game from the start.
    Nailhead Ronnie likes this.
  8. techg8

    techg8 The BS GS

    Lots of good info in my 200r4 swap summary thread from awhile back.

    You'll likely want hardened pump stator splines and an improved servo on the 200r4. But what exactly it will need will depend on what core you intend to use. If you can, get a performance coded one from a turbo buick, 442, hurst old's, corvette or monte ss. BQ, BRF, CQ, CZF, OZ are all performance units and there are more.

    I highly recommend CK PERFORMANCE out of new York for 200r4 overdrive info, parts, advice etc. CHRIS the owner is super knowledgeable.

    BRUCE ROE Well-Known Member

    For the street the 430, a switch pitch TH400, and a 2.56:1 axle will serve you
    quite well, minimum cost and max reliability. A 4 speed trans will want a
    3s axle to utilize the overdrive, need a lot of beefing up, but turn in slightly
    less gas consumption and engine rpm. Bruce Roe
  10. HotRodRivi

    HotRodRivi Tomahawks sighted overseas

    So have you tried the ole pick one up and run technique?
  11. Nailhead Ronnie

    Nailhead Ronnie Well-Known Member

    Haha no, but I heard of it.
  12. Nailhead Ronnie

    Nailhead Ronnie Well-Known Member

    Thanks Bruce, because of you the th400 just can't leave my list of possibilities.
  13. Nailhead Ronnie

    Nailhead Ronnie Well-Known Member

    Thanks guys, I haven't replied because I'm still up in the air about everyth ing, I really appreciate your time that you have given me to help.
  14. HotRodRivi

    HotRodRivi Tomahawks sighted overseas

    with a 3.08 rear and a 700r4 first gear is very quick. You have to shift earlyier than with the 400. someware aroung 40,45mph. With the 400 i would shift into second at around 55 mph max. Second also is quicker but the one thing I dont like is unlike the 400 you cant down shift to 2nd at 75 . You have to slow down to about 60 to drop to 2nd. And another thing that happens is 1st to 2nd has the largest differance in ratio of the 3 trannys. So it can drop your engine out of that power band to ware you will notice your engine have to catch up to itself. Thats usually ware the car your racing catches you , or gets a car length on you. You can get a planet and ring gear combo with a better ratio and not have that. But overall i will still go with the 700. I dont care what anyone says a 2004r behind a 455 in a 68 RivieraGS with all the upgrades and cost, well I just picture the clutches smokin and the little pinion gears in the planets straining , the really small diameter roller clutch just not having a good day. I need to see it to belive it. Also no one has yet to offer me one to try out. Plus I already know how to build a 700 that will live. Ive put 2004r's in smaller cars with plenty of success and would do it in a Skylark or GSX . The 4L80E , they only come in an E. So you need the computer. I also revert to the pick it up and run accross the shop with it. You will be slower. I would put it behind a Tomahawk. With a 700r4 , 15 inch wheels, 3.08 rear, 2000 rpm = 78 mph. And then you have Larry with the gear venders OD.
    Nailhead Ronnie likes this.
  15. Nailhead Ronnie

    Nailhead Ronnie Well-Known Member

    Part of me is so glad I haven't purchase a transmission yet. So much to consider. I know I've ask about manual transmissions on this forum and even made one at the same time, but guess what guys. I found out my wife is pregnant with our first so I was telling her my prioritys have changed and I'm going to go for an auto trans to save money and to see the car run with in 18years lol...
    I told her (we are Latino) "hey, I'm going with an automatic if we have a son, I'll just call him MANUAL"
    Thanks Guys, and I'm still in the air lol
    Thanks for everyone's help, I'm learning so much

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