I right now have a 267/TH200 in my 81. I am swapping that out for a 350/350TH with a floor shifter.
Should i might as well find a column from an 80's camaro with floor shift and swap that in for gear selector to make things easier on myself?
Someone said that there is a tranny vacuum canister of some sort(i just know old cars :oops: ). What can i do about this?
Any suggestions would be appreciated. Thanks

-Eric

You can use just about any GM column especially 78-87. On a th350 you just have a modulator valve that hooks to a intake manufold vacuum, thats it.

Erk...before you drop in that 350 with a 350THD tranny, think about what your use of your Elky will be. A daily driver, or a rock em sock em robot? Gas isn't getting any cheaper, and a 4 speed automatic tranny may be a better choice for your needs. If you want a better automatic trans and retain the overdrive go with a 700, if your building a performance vehicle and your not concerned with fuel economy I would go with a 400THD. Don't get me wrong, a 350THD is a good trans, but no matter what you pick for a trans, your still going to have to do whats necessary to make that trans work in your car, the 400THD IS better than a 350THD and a 700 IS better than a 200!

I'm using a TH350 non-lockup with a 2500stall this will be daily driven this will be a good choice on my setup.
I don't need a TH400. I don't need that much "meat" behiend my setup.
I don't want a 700r4, they have a tendacy to take up more hp than the 350,I don't really need overdrive as i will be doing almost no highway driving outside of the occasional dragstrip. The trans is the same length as the TH200 so i don't need to modify my crossmember or my driveshaft.
Gas already isn't going to be good with a .470 lift cam and a 650 double pumper.

-Eric

You can use just about any GM column especially 78-87. On a th350 you just have a modulator valve that hooks to a intake manufold vacuum, thats it.

Thank you, sound simple enough.

-Eric

I don't want a 700r4, they have a tendacy to take up more hp than the 350

Not really enough to notice.

But they do take up more than a TH350 it might be .5hp might be 10 its still more than with a 700r :lol: :P

-Eric

The th400 will use around 20 hp more than the th350. Not sure about the 700. I think a th400 should only be concidered if you are going to do some serious racing.

I am going to run a TH350 final. I just needed info in swapping it. I am only going to a dragstrip a handfull of times. Maybe once or twice.

-Eric

I am going to run a TH350 final. I just needed info in swapping it. I am only going to a dragstrip a handfull of times. Maybe once or twice.

-Eric

I will probadly swap to overdrive someday, but not while my th350 works so good.

Someone said that there is a tranny vacuum canister of some sort(i just know old cars :oops: ). What can i do about this?
Any suggestions would be appreciated. Thanks

-Eric

The only vacuum "canister" I know of is the modulator valve. Run a vacuum line from hte intake port behind the carb to the modulator valve. You can swipe a steel line from an older car or truck like an older elky or chevelle or something like that. Or just run a braded line to it.

Use a new Modulator valve and keep an eye on it. Some have been know to leak a bit causing transmission fluid to be sucked into the intake. That really sukkx and will burn the valves and rings if it persists long. I have had one or two go bad in the past.

The trans is the same length as the TH200 so i don't need to modify my crossmember or my driveshaft.


I had to change my crossmember to go from a TH350 to a 200-4R...I would imagine you'd have to change or modify it to do the reverse, also. You're right that the driveshaft is the same, though.

I just smoked the third 350 THM in my 76. (I am talking braking them in two) I will not tell you just what I think about them but a 700R4 is stronger normally and can be built up better and they have a better gear ratio. The 200R4s can also be built better and can get better mileage even than the 700R4 and still has a better gear ratio then the 350, 400 or the 700R4s.

By far the strongest is the 400 and the 4L80e. It soaks up around 20%-30% the 350 soaks up around 10/15% so do the 700R4s and the 200R4s. But then the torque converter has a lot to do with that too and the level of the kit inside, the rear ends etc... A ford 9" will consume more then a GM 12 bolt and more than the GM 10 8.5 and GM 10 7.5".

Then rolling resistance accounts for a lot of power loss at the track and launch suspension , dynamics.

Its tough to plan a ride that will do just what you want it to do both, on the street and the track. You will end up sacrificing somewhere, my experience, because the two places are mutually exclusive spots where you want two entirely different characteristics from the vehicle. I'd figure the sweet spot between the two and live with the end results.

If your producing less than or just at 450 Lb/ft of torque then nothing wrong with going with a GM 10 bolt 8.5" and a 700R4/200R4 with kits and a differential ratio of 3.73:1 to 3.92:1 or maybe a 4.10:1. Chances are your not producing that 450 Lb/ft at 2500 RPM so your probably not ever going to tear up that rear end or transmission. You get the minimum power loss through the drive train and all the components will handle the power output fine. You get good street performance and good track performance but not great I think with the right kit the 700/200R4s will get better ETs then the 350 THM or the 400THM. But I haven't actually done it myself so I can't swear to that. Number say its true.

Now the 700R4 and the 200R4s are more weight than the 350 but not a big difference between the 400 THM and the 700R4 weight wise.

Put it this way, I'll never run another 350 THM in one of my El Caminos again. I burnt up one and broke two fried four torque converters. I just don't care for them at all. A powerglide is a better transmission.

I'm just talking my opinions. :D