Transmission / Overdrive: Who makes the better transmission adapter. 259 289 V-8 to GM 400 THD

[Platech]

I see Myers and Bendtsen's have good looking adapter kits. Im going to hand a GM THD400 auto trans on the 1962 259 V8 (1954 Champion)
How do these kits compare. Myers with starter is $500. Other one I dont know yet.
Any help appreciated.

[Treblig]

I see Myers and Bendtsen's have good looking adapter kits. Im going to hand a GM THD400 auto trans on the 1962 259 V8 (1954 Champion)
How do these kits compare. Myers with starter is $500. Other one I dont know yet.
Any help appreciated.

Why would you go through all the time and expense to install a GM transmission and NOT use an GM overdrive transmission?? Just wondering......


Good Luck,
treblig

[karterfred88]

I agree, a TH350 or 400 isn't any better than the old BW, just lighter--unless you're secretly running 20 pounds of boost and nitrous. If its street driven the 200-700-R4 is a much better swap--and usually cheaper-unless you just happen to have a rebuilt 400 already.

[Mike Van Veghten]

Yea...kinda like Treblig said..!

Beside, a T-400 is the most difficult to rotate, or...it uses up the most hp to turn compared to a more modern trans..!
A well build T-200-4R is the way to go. Light, small, great gear ratios...how can you loose ?
It's what's in my daily driver and have an expensive one for my Hot Rod Stude.

Mike

P.s. - I used "41Frank's" (Drivers site name) adapters for my two cars. Aluminum, nicely done. He might chime in here, or just look up is name.

[41 Frank]

I believe we have one or two adapter kits left and after they are gone we're done. My partner in crime John's health is at a point where he just can't deal with manufacturing them any more. Cost is $325 + $15.00 shipping cont. U.S. Send me a private message if interested or details are on the Studebaker swap page where I advertise them. I believe last month was the last time I did that.

[BobWaitz]

I have one of Frank's kits and am very happy with it. It's attached to a 700R4. Whatever kit you get, make sure it uses a modern starter.

[sweetolbob]

Yea...kinda like Treblig said..!

Beside, a T-400 is the most difficult to rotate, or...it uses up the most hp to turn compared to a more modern trans..!
A well build T-200-4R is the way to go. Light, small, great gear ratios...how can you loose ?
It's what's in my daily driver and have an expensive one for my Hot Rod Stude.

Mike

P.s. - I used "41Frank's" (Drivers site name) adapters for my two cars. Aluminum, nicely done. He might chime in here, or just look up is name.

Agree with Mike. If you are upgrading use an overdrive. Around here even the drag racers use a built 350 instead of a 400. A couple of them claim about 15 HP penalty running a 400 instead of a 350.

[Platech]

All great help and info. Im all for modern, a GM w/overdrive thats lighter and more efficient. However its my cousin the mech, a master at 1960s Chevys and he insists the 400 is one of the best trans GM ever made. he is also tops inside this trans. So for $800 he gets it from his nearby supplier and will go over it and make sure its perfect, partial or full rebuild to his spec.. We will see about lowering the rear end gearing instead. I will have to stick with the 400 because it will be one he can work any day of the week and probably no cost. Im looking for a Ford Explorer rear end with disks for this car too. Just making this car a weekend driver.

[karterfred88]

Good luck and hope you are happy with your choice. For not much more, his supplier can probably provide a HD 200 rebuilt-just a thought. Changing the rear to a Ford 8.8 is a way to go-if you are also doing a front disc conversion. Look for a 3.31 if you actually plan on driving over 50 MPH without the OD trans. The 400s 2.48 first will make it a dog off the line, but at least you'll be able to travel on Interstates without ear ringing RPM.

[RadioRoy]

It's always tough when you have someone else doing the work. Then you have to build your car the way THEY want to build it. I will vote for the automatic overdrive as well. A straight through automatic (no overdrive) is a waste of opportunity, IMO. But the OP is pretty much stuck with what his friend thinks is best.

[wittsend]

Depending on the condition of the existing engine the best adapter may be none at all. It may be better to just use a small block Chevy engine.

Everybody has their expectations and price point but for me I got a '85 Corvette long block with 66,000 mile off Ebay for $177. I got a recently rebuilt 700R4/Convertor out of Pick A part for $80 - out the door. By the time I recouped from selling the original engine and trans they cost me $40 combined. Another $150 for everything else (intake, carb, driveshaft, shifter (floor mount), trans cooler, etc.). I gained about 80 HP and got a 4 speed automatic overdrive for under $200 - total. I also got the satisfaction of doing the modifications and install myself. So, while I wouldn't expect everyone to follow the method I did, it is at least an option to consider in some fashion.

[Platech]

Nice deal, wittsend...
Yep, well I know a lot of what to do. I restored a dozen FIATs and Alfas in my late teens from near junk to prestine as I enjoyed driving them for a year. But Im doing 60+ hours in business and need to have the cousin handle all this. I waited 10 years for him to get a decent shop, would not trust anyone else within 500 miles. The 1962 259 V8 in this car he is fully rebuilding and I could see it needs it. Got the Turner disks, and going for a Jems brake booster and twin pot master cylinder. And the Ford rear end, hopefully with disks. Thanks for the tip on the gearing. Im hoping to cruise at 60 at under 2000 RPM to enjoy the engine. Yes its a lost opportunity for the OD trans but that could still come later, a couple years, who knows. Found a 4 barrel manifold and carb for the engine too.
Got the Myers trans adapter kit, I called Bentzens and the other guy and couldnt get to them so I needed to move fast on this. We should have the trans and engine set up inside 2 weeks.

[Mike Van Veghten]

Hmm..
While yes...the 400 is hell for strong...going backward seems like...well, going backward.

I have a VERY high end Turbo 400 that I had built back when I had my Pro Gas Anglia. All high strength steel shafts, billet clutch baskets, the works. Should hold up to about 2500 hp.

But...is it worth putting into any of my Studebakers...na. Too heavy, too much parasitic loss (that is power used up just turning the guts of the trans..!).
Even my hot rod 54 Stude with custom forged pistons and billet rods, custom made intake manifold (?!), "highly" reworked cylinder heads, crank triggered ignition, streamlined crank counter weights, and on and on.
I had a high end T-200-4R built with a trans. brake. Should be good to about 1000hp...which my Stude engine will...never produce.
And I have HAD the T-400 for some time now...sitting, waiting..! I just thought that going to a better setup was the way to go.
But yes, it is your money, just don't spend it fo....

Something to consider...

Mike

[JoeHall]

Your friend knows what he is talking about. I ran a TH400 in a 56J over 40,000 miles, and loved it. Sure, there's other choices, but the TH400 has driving personality second-to-none, and was used in everything from Rolls Royce to GM. I'd suggest about 3.0 ratio rear end to mate with the 259. I ran a 2.53 in the 56J, but its motor has more torque.

The TH400's 2.48, automatic 1st gear start is same as manually pulling the stock FOM down into low. Yes, you can convert an FOM to 1st gear start, but its a PITA and will never work better than the TH400. Unless into drag racing, you won't notice the TH400's minor parasitic drag. Maybe one MPG, at worst.

I cannot overemphasize the importance of using the TH400's OEM valve body. STAY AWAY FROM SHIFT KITS; they will destroy the TH400's outstanding driving personality, and render it almost useless for anything but the drag strip.

[345 DeSoto]

There is a Stock 86 Monte Carlo SS 200-4R behind this engine...and it operates beautifully.