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Soooooo........looks like I have some decsions to make about what to do next.
New Motor clearly too much for the standard Turbo 350 or at least it was too much for my old gear box........I'm running a VERY HEALTHY 450+ horsepower in a 383 SBC.
30 years ago I'd have just driven it to local transmission shop and said, "Call me when it's done"
I'm not sure a rebuild at a local shop is my best path today though......
Today it seems like there are many ways to go besides just a standard rebuild and because I'm dealing with a whole lot more torque and Horsepower than before I'm wondering what my best route is. This car sees so very few miles a year.......I'd consider an overdrive but would rather spend the extra $ on a tougher 3 speed that can hold up.
Th350's can be built stout for not a lot of money. I'm pushing close to 700 hp on nitrous through one I had built by a local shop for $1000. Around 50 passes on it pulling low 1.40's 60 foot times.
Considering that now you may need a new torque converter (to prevent ruining a freshly rebuilt transmission) along with heavy duty clutches and planetary gears, you might want to consider an exchange in case some of the machined faces in the original case are now worn too thin to maintain proper end play. (That is info I learned from checking into rebuilt A.T.s).
You could disassemble the unit yourself and check the wear areas to see if they are worn past rebuild tolerances. If the case is rebuildable you could rebuild it yourself with a step-by-step instruction book....
I'm running my TH-400 for now and saving my money for my TKO-600 conversion.
I hope to have the funds to purchase the SST conversion kit by the end of the year.
I know my 496 would destroy an auto overdrive so I'm swapping to manual.
Save your pennies and get what you want, even though, like you, I'll only be driving it limited miles every year.
I think the th350 an be built well enough to live behind your 383.
I went from a th350 to a 700r4 thinking I'd save gas money,...ended up blowing two 700r4s in a year behind my 406. Went back to a th400 this time. Been in running at least ten years with zero problems.
Ask around locally to see if you can find a performance oriented trans shop. When I went looking and mentioned I had 540 horsepower most local shops backed out of doing the work, one said he'd do it, but no warranty.
So I ended up calling Rossler's and having them build it. He builds for top fuel cars and is worth every penny as far as I'm concerned.
Last edited by The Money Pit; 07-19-2018 at 12:19 PM.
That's the one.......just ordered it on Friday along with converter. Truck Freight from Texas so.......probably here by the end of the week at best.
I called TCI directly.....they suggested this very same unit. Funny thing though......Summit's pricing was actually better on it than the Manufacturer itself. So I ordered from them . I'll be using a 2400RPM stall Converter. Fingers crossed we'll have it by the end of the week and maybe all put back together within the week after. My husband won't install it.......says he doesn't want to wrestle with it. without the benifi of a "lift"......he's removed the exhaust and everything in the way already........I'll be driving it with open headers to the shop 3 miles down the road and then back home the same way......with only 1st and 2nd gear (3rd is all done completely GONE).........loud ride no doubt. Hopefully it's a trouble free R&R......the guy we know down there tells me it's 2 hours for him if everything is out of the way. We'll see.
Two hours sounds about right for a shop to R&R a TH-350.
Ive heard good things about the TCI's and You can't beat Summit Racing for their customer service and pricing.
Let us know how the new trans goes and enjoy.
Even a stock TH350 with a fresh rebuild and good clutches/bands will easily handle 450-500hp. Add a good shift kit as well.
Make sure to use a new converter and new trans cooler. You’ll be good to go.
i had a stock TH350 running 10.80-11.00s for years in one of my other cars years ago and it never failed.
The Converter will be new.......it's a shame really. The one I'm getting is the exact same one I've got in the transmission I'm having removed. It's got all of about 300 miles on it........but as you already know.......who can trust that bits and pieces of the broken transmission are all in the filter? So.......it's TRASH now too. (On the flip side......it's all anecdotal but the answer to the question, "how many miles can you get out of an older TH350 subjected to 450HP and few HARD LAUNCHES?"........appears to be, "Not many at all!"
I won't do a shift kit until I've lived with the new set up long enough to know how it works "as is".......certainly not within the 90 day warranty. It's not at all hard to imagine that'd be a warranty breaker. 3 months isn't long to wait yet it is a reasonable period within which a problem with build quality should show up if it exists.
That's the one.......just ordered it on Friday along with converter. Truck Freight from Texas so.......probably here by the end of the week at best.
I called TCI directly.....they suggested this very same unit. Funny thing though......Summit's pricing was actually better on it than the Manufacturer itself. So I ordered from them . I'll be using a 2400RPM stall Converter. Fingers crossed we'll have it by the end of the week and maybe all put back together within the week after. My husband won't install it.......says he doesn't want to wrestle with it. without the benifi of a "lift"......he's removed the exhaust and everything in the way already........I'll be driving it with open headers to the shop 3 miles down the road and then back home the same way......with only 1st and 2nd gear (3rd is all done completely GONE).........loud ride no doubt. Hopefully it's a trouble free R&R......the guy we know down there tells me it's 2 hours for him if everything is out of the way. We'll see.
Please post an update of how it works out. I am looking at that trans also.
That's the one.......just ordered it on Friday along with converter. Truck Freight from Texas so.......probably here by the end of the week at best.
I called TCI directly.....they suggested this very same unit. Funny thing though......Summit's pricing was actually better on it than the Manufacturer itself. So I ordered from them . I'll be using a 2400RPM stall Converter. Fingers crossed we'll have it by the end of the week and maybe all put back together within the week after. My husband won't install it.......says he doesn't want to wrestle with it. without the benifi of a "lift"......he's removed the exhaust and everything in the way already........I'll be driving it with open headers to the shop 3 miles down the road and then back home the same way......with only 1st and 2nd gear (3rd is all done completely GONE).........loud ride no doubt. Hopefully it's a trouble free R&R......the guy we know down there tells me it's 2 hours for him if everything is out of the way. We'll see.
I really struggled with TCI with a 700 R4 in my pickup. The first one knocked out thrust bearings in the warranty period. Good news it was warranted, bad new they charged me an additional $500 shipping and handling. They will not allow anyone locally to service the trans under warranty. You have to ship it back. The second trans would not shift out of low..... They wanted another $500. Summit racing stood behind the trans and got my money back minus the extra $500 shipping. Rebuilt the original myself and am running that one now. . Check the warranty. Check what you have to do if it fails. .You did the right thing by buying it through Summit. They were really helpful.
Make double sure the shop either flushes or (best option) replaces the cooler. Any trash that gets by the filter- and that's a lot of it- can and does get trapped in the cooler only to show up later, both killing your new trans and voiding the warranty.
Please post an update of how it works out. I am looking at that trans also.
Will do! It's taken a full week to get it here from Texas.........I just got the call from UPS today that it'll be delivered tomorrow. I have an appointment first thing Monday morning to put it in.
Make double sure the shop either flushes or (best option) replaces the cooler. Any trash that gets by the filter- and that's a lot of it- can and does get trapped in the cooler only to show up later, both killing your new trans and voiding the warranty.
Yeah.....I'm way ahead of you on this one......I'm actually replacing the cooler and flushing the transmission lines and radiator is on the list of things to do already.
Yeah.....I'm way ahead of you on this one......I'm actually replacing the cooler and flushing the transmission lines and radiator is on the list of things to do already.
So here is "update #1":
Got everything together.....only not included in this shot is a new Transmission cooler.....it's already installed in the car but not yet hooked up. The ride to the shop would only serve to fill it with what ever might be floating in the toasted transmission fluid of the current transmission. Tomorrow morning I'll drop it off to be put in. Barring problems I should have a first impression of things later in the day,
For anyone wondering which transmission we're doing here........this is the order number from TCI. It's the 6 inch tail shaft and it's supposed to be good for well over 700HP..........it should do the job for my 455HP 383. We'll see,,,,,,fingers crossed!
Ok, so I've had a couple of days to drive a bit (just a bit really it's HOT and HUMID here over the last 2 days and I've got no A/C in the old Corvette).........but I have got some first impressions for anyone interested in the TCI Super Street Fighter......It works and it doesn't leak.......(that's got to be the biggest win early on)
It tight shifting but not crazy hard shifts, really only a little more so than you might expect from a standard issue new Automatic in any car.
I went with the same stall speed and manufacturer of the torque converter I'd used previously so that part isn't part of the variation from before. Over all I'm pretty happy. I wasn't looking for that super hard "shift kit" type chirp of the tires between gears and this trasmission doesn't deliver it. If you want that you'll still have to go with a "kit".
The model number is one to remember........it's an exact fit with no surprises or modification of anything required. Only your dipstick tube will need to be transferred from your current transmission. The advertised/promised strength is supposed to give you room for a 700+ HP engine........more than enough for my 455HP dyno'd HP 383.
Read comments on Summit's site and you'll hear some horror stories about leaks but TCI has been around for as long as I can remember.......if those stories were actually "typical" experiences it'd be pretty hard to imagine the company would have lasted this long or gotten this BIG.
So here it is one more time. It works EXACTLY as promised. It fits and is an exact bolt it without modifications required and it doesn't leak.........a WIN for sure in so far as I can see.
07-18-2018, 06:58 PM
Automatic Transmission just ......STB!!
(On the flip side......it's all anecdotal but the answer to the question, "how many miles can you get out of an older TH350 subjected to 450HP and few HARD LAUNCHES?"........appears to be, "Not many at all!"
