Last night I blew 3rd gear in my 83ta, which has a T5 and a 305 producing 169 rwhp (i just got it dyno'ed that day).

The gearbox was rebuilt a year a ago for about US$900 (only 6 months warrany ), and they replaced 3rd gear. I don't know if they used bad components, or whether the t5 is just weak (obviously they never put them behind 350's).

Anyway, I have always thought about dropping in a 350 and an auto, and word has it that the turbo 400 can be made to take some serious abuse.

What I need to know is apart from the th400, stall, and rebuilding costs, what else should i factor in before i start looking into this (ie, shifter, tailshat etc etc)

Also, can i put the th400 in with the 305, and then swap to a 350 at a later date. Do they bolt up to the trans the same? What mods would I need?

 

Well, it was a fairly easy swap for me. I had a 200c auto in mine but the torque converter blew apart. I used my stock driveshaft but had to put on a TH400 slip yoke on, length was just right though. Got the Spohn crossmember and torque arm which bolted up just right except for having to bend apart the two plates that slipped over the rear end housing for the torque arm. Great thing about Chevy is their auto trannys will bolt up to small blocks and big blocks So no problem with swapping from a 305 to a 350 or even a 454 later down the road.

If I were you though, I'd get a TH350 tranny, they take less hp to turn and can be built plenty strong. I'm going to be putting a BBC with 500 - 700 hp in my car some day so I went with the TH400. As for the shifter, just get one out of an 82 which only had 1 2 D and no overdrive. Or you could get an aftermarket one. I'm using a Hurst Pistolgrip quarter stick just because I wanted the reverse lockout. There are adapters for the stock torque arm that can be found in Jegs or Summit Racing that bolt up to the transmission. You'll have to get a transmission cooler and bend up some hard lines plus possibly put a plate over where your stock shifter went throught the floor. Can't really think of much else so hope this helps a bit. If you want any photos of how mine is all done up, just ask.

 

thanks for the info

I'm not sure what sort of shifter i'm going to run, it would be a lot easier to run an aftermarket hurst or b&m than source an 82ta down shifter here in australia. It would be good to see how yours has come up through the console, so if you have any pics....

How have you found the 2500 stall? I was thinking of running a 3000 cos that were my 305 starts pulling well. Are you going to run a bigger stall when you change your motor???

As for the TH350, I am eventually looking at putting in a 395 horse LT1 or somthing similar, and the cost of a TH400 is only slightly more. Better to get something stronger than blow another transmission

 

I'd also recommend the TH350 in your situation. I ran one for a while but decided to upgrade to a TH400 when I wanted a transbrake.

The TH350 is a much easier swap.

 

TH350's can handle 500 hp if built properly (friend ran his behind a 454 for a long time) As for the 2500 stall in my car, heh... I only drove the car for 2 weeks before the transmission went bad and I've been waiting and waiting for the transmission shop to get my car done. Now I've put on a 10 inch converter which is a 2500 stall instead of the 12 inch.

Never drove right from day one so I don't know how it really was. I made a video the day before it fried and it was showing a pause in the RPMs between 4000 and 4500 rpm. Next day the RPM's never went above 4000 when showing my mechanic buddy the problem. Had a nice cloud of smoke behind me so I drove right to the transmission shop. That was 2 months ago, still no car to this day. I'll tell you how it is when I get the car back and I'll get pictures tomorrow of the shifter when I go over there to yell at the owner of the shop

 

I cant believe they've had your car for two months, I cant stand leaving my car anywhere for more than a week! Hope you get it back soon

You both recommend the TH350. I am relavtively new to all this, what is the technical difference between the TH350 and the TH400??? I take it the TH400 is a heavier duty box, and thus provides a larger loss in power between the engine and drivetrain, whilst the TH350 will provides less loss, but is only good up to 4 or 5 hundred hp???


PS Checked out your web site Stephen, thats one tuff lookin IROC

I attached some pics of my car from when I was painting the turbo fin wheels. The damned thing is gonna be sitting there for a while until i get the transmission going

 

I strongly recommend the th350. I had the 200c transmission too. What a miserable trans. I swapped in a th350 w/ b&m holeshot 2000 overstall w/ a shiftkit. I had the th350 rebuilt to take 600hp. I absolutly love the th350. I own an 82 z28. You will have to order a torque arm mount from jegs or someone.

 

Thank you. I have many fans of my car and many that wish theirs ran as quick.

I've rebuilt both TH350 and TH400's. I like the internal design of the TH400 better. They both operate in roughly the same way but the TH400's internal design can take a lot more abuse.

Weight wise the TH400 is only about 20 pounds heavier and only takes about 20 more HP to turn. If I really wanted a 10 second timeslip I'd either put a TH350 back into the car or go with a powerglide. The reduced drivetrain loss would be enough to put the car into the 10's. Both are not options at this time since I've already invested in a transbrake for the TH400.

The 2002 race season is over and I need to pull my tranny apart again. I had the pan off last weekend to change the filter and there's a bunch of brass in the bottom. Looks like a cooked a thrust bearing or something. I put it back together for the last race. I figured I couldn't hurt it any more than I've already done.

 

A bunch of metal went through mine after some splines had broken off on the output shaft Talked to the shop owner today and he wouldn't give me a straight answer on when I'll get my car back. Did see him working on the valve body though so that was good. This whole TH400 swap started 6 months ago Half the time I've been waiting on the tranny shop. Anyway, here's a picture of my Hurst shifter and the black anodized aluminum trim plate. My interior needs a bath now that I look at it hehe.

 

Sounds like the TH350 might be the way to go, as I am only aiming to put in an engine that produces about 400hp.

EvilCartman, thanks for putting up the picture of the shifter. I have had a look around and I'm thinking about the B&M console megashifter. This unit is specifically designed for 3rd gens, and looks well suited to the console, not too sure about the different features though??? Hopefully the grip will be comfortable as my car is right hand drive.

I noticed the electric antenna switch on your console is worn out alot more than the window switches. My TA is the same, you'd think that they would wear just as much as each other

 

Actually, that's the rear hatch button in the very middle The car I think was never covered and the sun really did some damage on the interior. The rear seat was sun rotted and the door panels are all discoloured. I've redone the seats but that's about it for the interior repairs so far. The button still works so it hasn't been very high on the "replace me" list. The B&M unit should be fine for ya, pretty comfortable unit and you don't have the extra lever on the side like mine. Good luck with the swap

 

Thanks,

stay tuned, i'll let you know how i go... probably in about 4 weeks



PS

My cars interior is sun faded too (and quite evenly which is weird, you can only see the original colour underneath the headrest). It's gone from grey to some sort of a beige light purple colour, its hard to describe. A tan leather interior to go with the gold stripes is another thing i need to do, but thats a whole other topic

 

Well, I can tell you how the 2500 stall fells now I just got my car back today! the 10 inch 2500 stall really helped it get out of the hole better it seems like. It let the engine get into the power quicker so it just takes off. Shifts on normal driving are pretty soft but when you get on it, they're nice and firm. Have some carburator tuning to do now, it's running really rich from when I was messing with it before the transmission went bye bye. Damn it's good to be back in the driver seat

 

I know the feeling evil. Sounds like our 82 z28 are going through the same thing. I love my 2000 overstall. Do your tires squeal coming out of first when you get on it? I think the only real complaint I'll ever have about my camaro is the frame and lack thereof. **** poor frame design.
Glad you're enjoying that new trans. My carb is running rich too.

 

Well, I'm not enjoying it anymore. After I made that post, I went and re-jetted the carb. Took it out for a spin and the transmission has the same damn problem as before. Did pull a lot harder though with the properly set up carb. I took it right back to the transmission shop today and told him what was going on. (certain point in 1st gear the tranny feels like it's fighting itself) Friend of mine wanted to see what it's like so we took a drive with him doing the driving. Hour later, the tranny guy drove it to another shop to ask them what they thought. Turns out a possible cause is a pressure bleed over that's causing 1st and 2nd to try and be engaged at the same time. When this happend before, the 1st and 2nd clutch packs were burnt up. So now it all has to come back out yet again. Drives fine with normal driving but once you get on it, it's like someone is putting on the brakes at about 3500 rpm and above in 1st. This sucks

 

electric antenna switch ?! haha..

 

??? My car has an electric antenna switch between the power window switches. My rear hatch switch is underneath the gauges. If this isn't normal, it's probably cos my car is a right hand drive conversion.

Anyhow, sorry to hear about your car Evil. There's nothing worse than getting you car back and having the same problems as before.

Hope you get it going soon....

Damn i hope my cars on the road soon too, still savin $$ for the swap over.

 

Hey guys,

It's taken me a while to get around to making this post, but the Tubro 350, 2500 stall and a B&M Console Megashifter have finally been installed (this was late last year!).

I am really pleased with the whole setup. The stall is perfect, give is full throttle and it'll happily go straight to 3000, which i didn't expect, mid-throttle will put it to 2500 (obviously I hadn't driven a hi-stall car before).

Don't really miss the 5-speed, as the stall and shifter make up for it fun wise, although an over-drive would be nice. You also get instant power with the stall without having to shift down a gear. The car sounds a hell of a lot tuffer.

Had a shop do the fitting and they did all the necessary mods, all i need to do now is put a console plate in, and i will post some pics when thats done (probably in a couple of months seeing as i will be going overseas soon).

Anyway, thanks for all the advise...