200R4 swap

[TOG 6]

Good morning-

For those of you who swapped your TH350 for a 200R4...

79 / 403
Other than the tranny itself and moving the crossmember what did you need to make it work?
Shifter mod / parts?
TV cable replacement / modification?
TC lockup?   No lockup?  Pats / mods?

Thank you in advance

[737driver]

Bowler Transmission makes a great TV cable setup . Their setup provides the right geometry for the cable on the carb or throttle bottle. It automatically adjusts the right amount pull for the TV cable. Definitely worth looking into.
Jim

[Wallington]

If you have your original Olds Q-jet...good to go.

[NCBadBird1979]

I did a similar swap on my '79 Trans Am that has a Pontiac 400. It had a TH400 and I went to a 200-4R. My main reason was so I could run 3.73 gears and have good gas mileage for highway runs with that gear set up.

The mods I had to do for mine were:

-- Correct length TV cable

-- Had to buy the shifter conversion set to have overdrive labeled on the shifter and so it will lock in place when put in gear. Link: https://www.classicindustries.com/product/all-years/pontiac/firebird/parts/SC226.html?gclid=Cj0KCQiAweaNBhDEARIsAJ5hwbdXy1gy_cySEbNote1fR6Gdc489FIDjQ6dP9vKB47EIYIlo7POxK2QaAiZZEALw_wcB

--You will need something to activate the lockup on the torque converter. There are different options out there, but I went with the B&M controller for easy full control of lockup. You can set it to lockup at the speed of your choice and turn it off and on whenever you want. It's easy to wire up as well. I have my control hidden in center console armrest storage compartment. Link to the B&M:
https://www.summitracing.com/parts/bmm-70244

--I had to put a higher stall converter due to the aftermarket camshaft I'm running. I also had the 200-4R rebuilt with performance clutches/bands and billet internals parts from CK Performance due to the horsepower range I'm in. A Google search will bring up their website. You should be ok if you're stock or not too far from it, but someone else can chime in if I'm wrong.

I learned that the 200-4Rs are really funny when it comes to trying to get the shift points where you want them. What valve body & governor combination is in it, and rear gear used will determine it. The most sought after 200-4Rs come out of Grand Nationals, Monte Carlos and 442s of the early to mid 80s. There's not really any reproduction parts out there for the 200-4R valve bodys and governors. A Google search on the shift points and shift point modifications of the 200-4R will bring up various ways others have adjusted theirs to the range they found suitable for their set up in the event its not where you want it after install. I was lucky that mine was right where I wanted it.

You shouldn't have to move the crossmember but some have to.

[rkellerjr]

I did a similar swap on my '79 Trans Am that has a Pontiac 400. It had a TH400 and I went to a 200-4R. My main reason was so I could run 3.73 gears and have good gas mileage for highway runs with that gear set up.

The mods I had to do for mine were:

-- Correct length TV cable

-- Had to buy the shifter conversion set to have overdrive labeled on the shifter and so it will lock in place when put in gear. Link: https://www.classicindustries.com/product/all-years/pontiac/firebird/parts/SC226.html?gclid=Cj0KCQiAweaNBhDEARIsAJ5hwbdXy1gy_cySEbNote1fR6Gdc489FIDjQ6dP9vKB47EIYIlo7POxK2QaAiZZEALw_wcB

--You will need something to activate the lockup on the torque converter. There are different options out there, but I went with the B&M controller for easy full control of lockup. You can set it to lockup at the speed of your choice and turn it off and on whenever you want. It's easy to wire up as well. I have my control hidden in center console armrest storage compartment. Link to the B&M:
https://www.summitracing.com/parts/bmm-70244

--I had to put a higher stall converter due to the aftermarket camshaft I'm running. I also had the 200-4R rebuilt with performance clutches/bands and billet internals parts from CK Performance due to the horsepower range I'm in. A Google search will bring up their website. You should be ok if you're stock or not too far from it, but someone else can chime in if I'm wrong.

I learned that the 200-4Rs are really funny when it comes to trying to get the shift points where you want them. What valve body & governor combination is in it, and rear gear used will determine it. The most sought after 200-4Rs come out of Grand Nationals, Monte Carlos and 442s of the early to mid 80s. There's not really any reproduction parts out there for the 200-4R valve bodys and governors. A Google search on the shift points and shift point modifications of the 200-4R will bring up various ways others have adjusted theirs to the range they found suitable for their set up in the event its not where you want it after install. I was lucky that mine was right where I wanted it.

You shouldn't have to move the crossmember but some have to.

Good list, basically the same for me and my '75 Trans Am with a 400. I replaced my TH350. I did have to move the tranny crossmember but the 200-4r bolted right up to my 400, drive shaft worked great as well, no changes there.

[scarebird]

...You will need something to activate the lockup on the torque converter.

no, you can get a brake switch with 2 switches; one shuts off the lockup.  IIRC there is 4 wires going to the lockup - you can have it lockup in 3rd and OD or just OD depending on how you wire it.  Mine was initially both, but that was kinda jerky so went OD only.  Around town I leave it in 3rd, saving OD for travel above 50mph.

Also, lockup is not strictly needed - you can run it without.

[TOG 6]

Thanks, everyone. 

[Wallington]

same brake light switch as used in cruise control cars.

[TOG 6]

If you have your original Olds Q-jet...good to go.

meaning, what. exactly?

[Wallington]

The TV cable adjustment and conversion kits match the original Oldsmobile Q-jet linkage. Except those selling the kits forget to mention it. The 307 Olds cars that the transmission was first fitted to used the same linkage geometry. The arm is slightly different shape to account for different return spring location and different fast idle solenoid used, but the relative locations of throttle shaft, throttle cable and TV/kickdown, are the same.

A very general comparison pic between 80's 307 with 200-4R and 70's 350/403 with TH-350. The return spring hole is moved and the idle-solenoid setup different. The later version also ran the TV cable to the outside of the linkage as used a wider cable mount bracket. Just swap the 200-4R bracket in place of stock and good to go.

https://www.amazon.com/TCI-376700-Transmission-Bracket/dp/B000NZXKP4

Quadrajet Throttle shafts 307 2004R vs 403 TH350 (3) by Aus78Formula, on Flickr

[silver78]

some more tech data for an OD transmission. If you need to mod or make your own TV bracket this will help.

[TOG 6]

Swap went well - the crossbowmen was the hardest part, with the nuts on top and the bolts coming up from the bottom.
Thanks everyone.

[rkellerjr]

Swap went well - the crossbowmen was the hardest part, with the nuts on top and the bolts coming up from the bottom.
Thanks everyone.

Good to hear!

[scarebird]

Swap went well - the crossbowmen was the hardest part, with the nuts on top and the bolts coming up from the bottom.
Thanks everyone.

...and I thought Albuquerque was a tough town!

[Wallington]

so...what are the details of your swap?