[awoodman]

I just built up a N/A sbc 350. Im thinking it should put out something like 400 horsepower. It is hopefully going to go into an s10 or blazer to become a street/strip truck. If i cant find an s10, possibly an iroc. I need a tranny for it. I know a guy that is selling a turbo 350 transmission with 50k original miles, not rebuilt, short shaft, and it has a lockup converter on it. He sandblasted the whole thing and painted it and it looks like new. He wants $150 for it. I heard you need a special distributor for this, as that's what tells it to lock up. Is that true? I also heard lockup 350's don't last as long as the regular non lockups. I wouldn't mind the extra mpg's on the highway, but don't want the tranny to blow up. Should I buy this tranny and use it? Or should I wait and find one thats non-lockup?

[F&J]

BTTT;

I hope you get some answers; I'd love to try one in my 63 suburban. I've got a 400 sbc TH350 with 2.76 gear. It still needs a little more. I've tried 700r4s in other old chev trucks, but I don't care for the wicked low 1st gear. I'd really like to try the 350C....

[DrivFast4U]

There are tons of cheap 4 speed automatics out there. Why would you want to settle for a 3 speed?? The lock up 350 was a last ditch effort to meet increasing cafe standards in the late '70s. There is a good reason you haven't seen one in a new car for decades. Besides, "looks like new" is not worth $150. These trannies are not worth that much. A couple cans of solvent and and some spray paint can be had for under $10. Buy a dirty post 1985 700r4 and make it "like new" yourself. You'll be happier.

[Fergusonic]

I control the lockup in my TH350C tranny with a B&M Lockup Control. It senses the mph. You can adjust it to what mph you want it to lockup at. It costs $175.95 thru Summit. The lockup will reduce the rpm about 200-300.
Or...you can run the TH350C without any juice going to it...it just won't lock up. I don't think a Lockup would improve a 400 HP engine's gas mileage.
Weaker than TH350?....I dunno. Will hold up to 400HP SBC?...I dunno.

[briscoe]

The 350c[lockup], in stock form, may do just fine behind 400hp.

But that depends on you and how rough you are with it.

The weak area with any 350 is the intermediate sprag race, which can break and leave you with no 2nd gear.

Usually when a 350 is used behind 400hp a hardened sprag race is a good choice as well as doubling the bushings in the sun gear, a wider bushing in the direct drum, a stiffer pressure regulator spring in the valve body, for higher pressure, a little calibration work to the vb, etc.

Again, if your not to tough on it, the 350c will do just fine.

But with gas at around $3.00 a gallon I think I would get that lockup feature working.

[awoodman]

Thats the thing is I will be beating on it. It's going to be primarily a street/strip build, so when i'm on the strip, ill b beating on it, as well as when i'm on the street most likely. Is the work I should have done to the transmission Do-able by me? Or would I need to have a transmission specialist do it? I would like to keep the money i spend on the tranny minimal because I already spent so much on the motor and eventually a truck and rear end and all that. Thanks for the help!

[briscoe]

Please forgive me if I come across as being smug, but as a transmission guy, you would not believe how often I hear the very same thing that you have just written.

Tons of money get's invested into the engine and so often there is nothing left for the trans.

Anyway, your question was, can you do the work yourself?

Lots of people that post on this site have successfully rebuilt their own trans and, you can get good support from the trans people that visit this site, as well.

But, if you're gonna beat on it you better go thru it.

[awoodman]

Okay great. When you say double the bushings in the sun gear, do you mean like put two side by side? Or get one that fits into the other. I have never seen inside a transmission before, unfortunately. I imagine there are guides or book that you can buy, right?

[briscoe]

The sun gear has, from the factory, a bushing installed on either end.

By installing two bushings on either side and drilling the lube holes that you have covered up, because of the additional bushings, you will make this trans more durable.

Go to the search feature, located at the top of this page and type in jakeshoe.

Then click onto the thread that is at the top of that page.

I think it is titled first time 350 rebuild, or something like that.

This thread will cover a lot of your questions, I think.

[DrivFast4U]

Let me get this straight. You want to puposely buy a week 3 speed transmission because it's cheap and "looks like new". Then you want to break it open, and spend a bunch of money to make survive behind your 400hp engine. If you want a cheap, very beatable 3 speed, just pick up a used TH400 for $50 from a junk yard and you'll have to do nothing to it. The TH400 Will easily handle 400 hp thrown at it all day long with no modifications at all.

[awoodman]

well i read that a th400 sucks up a lot more power than a th350. I looked up the parts that briscoe listed and they are cheap parts. a sprag race seems to be the most expensive part at about $40. Oh,and i've been told I'll want a 3000rpm stall converter. Do I need a special lockup converter? Where can I get one?

[awoodman]

Okay, so I've bought the Ron Sessions book "Turbo Hydramatic 350" and gone through some of it. Is the th350 internals the same as the th350c internals, such as the parts I'll need? So let me get this straight...I'll need to get the following parts and nothing else?...Hardened Intermediate roller clutch race or sprag race, Bushing kit, thrust washer kit, 2 extra sun gear bushings, .75" wide direct drum bushing, performance shift kit(which one?), and a standard rebuild kit(which one?) What is a good site to get all of the parts I'll need? Thanks again

[awoodman]

Actually, I've gone to bulkpart.com and put these items into my cart. Can someone who knows what they're doing please take a look at these and let me know if these are the correct parts I'll need for this rebuild? Thanks for your time.

44030A Bushing kit, 250C / 350C 1980-up with Lock-Up
$10.09 $10.09
44046C Bushing 350 series direcr drum WIDE
$1.36 $1.36
44052 Bushing 350 series, Sun gear & rear planet
$0.80 $1.60
AHP47001R-K ALTO HP Master Kit, 350 / 350C w/ Red Eagle Friction & Kolene Steels
$135.50 $135.50
A44663HD Outer race, Hardened - intermediate , 350 / 350C
$22.76 $22.76
T44171A TransGo Reprogramming Kit 350C 81-up Performance / heavy duty kit 350C-1&2
$58.00 $58.00
44200B Thrust washer kit, 350 series, 1980-86
$14.18 $14.18