# 67 Tempest transmission swap



## 67T3MP3ST (Jan 2, 2012)

I am new to the forum and getting ready to restore a 67 Tempest with a 326. When all is done with the engine it should be around 350 hp. The car currently has the powerglide with column shift 

I am deciding between the TH350 and a 200r4. I would like to have the overdrive on the 200r4 but from what I understand that involves moving the crossmember back and I am not excited about drilling new holes in the frame. Does the TH350 need the crossmember moved at all or is it a complete bolt on?

I also plan on switching to floor shift with a his/hers shifter and I think I need to buy the kit from shiftworks to make this work.


Has anyone done this before and can you please provide any insight.

Thanks


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## danthepontiacman (Jul 5, 2008)

first off is that 350 hp out of the 326? if its the original automatic to the car and its a 2 speed then its not a powerglide has pontiac never used a chevy powerglide, they used the buick st300 two speed. if its the originalst300 then the crossmember dont have to be moved to put a th350 in, i been considering a 200r4 in my 66 tempest and been reading bout it, im not crazy bout drilling in the frame either and found that you can buy a aftermarket crossmember that will fit a 200r4 without having to drill new holes in the frame and if you use a his hers shifter there on convershion kits to convert one of those to work with a 4 speed auto.:cool


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## geeteeohguy (Feb 2, 2008)

A 200r4 will have to be worked over and upgraded quite a bit to handle 350 hp. They failed when they were behind 135HP 305 small blocks. They can and are a great upgrade, if built right. Not cheap, but your wallet will love you every time you cruise by a gas station without stopping to fill up.


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## Instg8ter (Sep 28, 2010)

not sure but you may need the driveshaft re-worked for the 200R4 the TH350 is a straight drop in and go and you probably all ready have a Salt flats rear gear 2:56 or 2:7X so you would still be fine on mileage and freeway driving. They are cheap reliable and lighter mass than a TH400 . All depends on budget and what you want to do with the car. Shiftworks has everything you need for the shifter when you decide which route you are going.


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## pontiac (Mar 6, 2011)

unless your ST300 is bad, not worth the expensive since the original dual gate alone is worth the price of a trans. not worth it for gas mileage either.


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## 67T3MP3ST (Jan 2, 2012)

It is the stock 326 with the 2 speed 67 Tempest 2bbl Its a matching numbers engine so I am going to keep it and rebuild it with a 4bbl. Stock it had 250 hp so the goal is 350 hp but I will be happy with anything over 300. (Heads redone with port/polish, cam, intake manifold, carb, headers, exhaust) But I will start a thread for the engine build when I get there.

Its a column shift automatic 2 speed transmission. I would like to change it to a floor shift with the hurst his/hers shifter and console. Going to get the shiftworks kit to make this happen.

I found a 67 column for floor shift but if anyone can help with where to get column bearings I would appreciate it. Also if anyone has rebuilt a column let me know too.

Back to the transmission. Sounds like the TH350 is a direct bolt in so thats what I will be going with. Now just got to find one. Also what stall should the converter be with engine I have planned? Was thinking of going as aggressive as 3.73 gears in the back b with a limited slip.


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## Instg8ter (Sep 28, 2010)

make sure you get a BOP TH350, the bolt pattern is different on a chevy trans...


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## geeteeohguy (Feb 2, 2008)

3.73 gears are excellent if you drive the car in town or not very often. They are miserable on the highway without an overdrive trans....you're comfortable cruising speed will be about 58-60mph. Long trips will be a real grind. BTDT. Also, be prepared for poor fuel economy and accelerated engine wear, all compliments of a steep rear gear. My advice?? 3.23's in your rig with a TH350.


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## 67T3MP3ST (Jan 2, 2012)

Instg8ter said:


> make sure you get a BOP TH350, the bolt pattern is different on a chevy trans...


I can just get the BOP bellhousing correct?

As for the gears the car will be my second vehicle for pleasure cruising. I live in Vegas so there is traffic most of the time. Just want to be able to jump on the accelerator occasionally off a light. 

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## 67T3MP3ST (Jan 2, 2012)

67T3MP3ST said:


> I can just get the BOP bellhousing correct?
> 
> Sent from my DROID BIONIC using AutoGuide.Com Free


Actually it looks like its all one piece. Thanks for the heads up 

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## likethat (Oct 5, 2007)

I have a BOP 200r4 for my 66GTO. I drilled the holes. There are 2 sets there already what is 1 more. I drilled a hole in the center of the original cross member also for the 200r4 tranny mount. The original drive shaft should be the work no mods. I bolted the engine and 200r4 together with the motor mounts and installed the whole thing. I moved the cross member till it was centered to the tranny mount made sure it was the same length both sides from the original mounting holes. I marked the location with the mounting tabs on the cross member then transfered the holes on the bottom side and drilled. It was super simple. Its your car but the extra holes will not hurt any thing. They are easily filled back in with a mig.


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## 67T3MP3ST (Jan 2, 2012)

*A Little Update*

Haven't logged in for some time. Here is the update and I need some help.

I decided to scrap the 326 because I got a deal on a 455 out of a 73. Just got it back from the shop and it dyno'd at 430HP with close to 500 ft lb of torque. Its hooked up to a BOP th350 with a 2900 stall converter. The old 10 bolt is still on the back, I figure I will drive it till that thing blows and then switch to a 12 bolt or a 9" Ford. I also have a chevy th400 sitting in my garage that I will hook up with the adapter plate if the the 350 I have goes out too

So I am stuck on where I should mount my dual gate shifter. I have the console and buckets. Should I just mock it all up and then bolt it in where I think it should go ? Do I just put a hole in the floor for the cable ?


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## BearGFR (Aug 25, 2008)

Unless you can find another car with the same shifter, or get someone who has one to take measurements for you, then yes --- mocking it up is the way to go.

Bear


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## ALKYGTO (Mar 29, 2010)

67T3MP3ST said:


> Haven't logged in for some time. Here is the update and I need some help.
> 
> I decided to scrap the 326 because I got a deal on a 455 out of a 73. Just got it back from the shop and it dyno'd at 430HP with close to 500 ft lb of torque. Its hooked up to a BOP th350 with a 2900 stall converter. The old 10 bolt is still on the back, I figure I will drive it till that thing blows and then switch to a 12 bolt or a 9" Ford. I also have a chevy th400 sitting in my garage that I will hook up with the adapter plate if the the 350 I have goes out too
> 
> So I am stuck on where I should mount my dual gate shifter. I have the console and buckets. Should I just mock it all up and then bolt it in where I think it should go ? Do I just put a hole in the floor for the cable ?



:agree Must mock it up for driver comfort, you can put a cable shifter anywhere, but the cable cannot be bent or curved too sharply and be sure to keep it away from the exhaust and don't let it rub on anything.

Nice drivetrain upgrade btw, it will feel like a totally different car. :cool


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## geeteeohguy (Feb 2, 2008)

If you have a forum/club member with a '67 GTO near you, that would be a huge help. Yes, it's one small hole in the floor, but it has to be in the right place so the cable doesn't get kinked.


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## 67T3MP3ST (Jan 2, 2012)

Thanks for the help guys. I will post some pictures soon


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## 1966 326 (Feb 23, 2018)

When you say, "if you have a his/her shifter" do you mean there is a conversion kit for the th350 or the 200r4?


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