PONTIAC 200 4R or Manual Trans?

g0thiac

Apprentice
Sep 6, 2020
86
8
I'd like to keep my car original, and numbers matching.

But the TH-200 in the car wasn't maintained by the previous owners well, the fluid in it and the 305 didn't look pretty.

And occasionally, the transmission isn't as responsive, as it is on other days.

So I'm just planning to drive it, and see when it's time to replace.



But i'm choosing between TH-200 4R, as I would like overdrive since I have done quite a bit of highway driving. That said I'm also considering a modification for a manual transmission.

What do you guys think would be the better option, long term? I need something, that I know if maintained, won't break down on me for a long time. Thanks.
 

64nailhead

Goat Herder
Supporting Member
Dec 1, 2014
2,273
113
Upstate NY
Either wil last a long time in a sub 400hp build. Couple of things, if your car has a crazy tall rearend, as most G-'d=s had from the actory. I.e. 2.29, 2.56, etc. and yo intend to keep a short tire, sub 26", then a non OD 4 speed manual will add a gear and function well. The 200-.4R with a .67 OD gear flat out will need a rear gear swap unless you already have swapped the rear and tire size to something lower gear wise and taller tire. The manual will cost more unless you can pickup a functioning used candidate. You can get into a rebuilt 200, converter, TV cable and related parts for under $2k easily.

What is your rear gear and intended tire size?
 
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ssn696

Living in the Past
Supporting Member
Jul 19, 2009
4,756
113
Mid-life crisis
I searched the Forum for all your postings, so I could compile the big picture. These cars are getting rare, but are not collectable. Treat yourself as the end user. Assume every dollar you spend is gone and never coming back. That said, hack both of them into what you want them to be to make your life more fun. You mentioned a disability. Make every CAD go toward your end goals. So, grab a pencil and paper and hatch a plan before you start shoveling the money.

Since you have two cars, maybe keep one stock/automatic and make the other a manual. Rowing is really fun and no one expects that from a 'grandpa car'. Since the manual was never an option in the B-body, go manual in the G-body, which was offered with a manual option.

I'd suggest figuring out which car's 305 is in better shape. Caprice/Impala, as a 1988 model year, will have the roller cam with a TBI. I don't know if you have to comply with emissions in Ontario, but you might want to go large in the Caprice and use the TBI 305 in the Bonneville. You might consider a 700R4/4L60 in the Caprice. The 3.06 first gear is just the thing to move a brick of iron from a traffic light without a rear gear change. Need to shorten the driveshaft and swap crossmembers.

Then use the 200-4R - or think about a Tremec T5 in the Bonnie. You will need the find parts: bellhousing/flywheel/pedals/linkage. If you keep your HP low, you don't need to scour the world for a World Class version, which is only stronger by 150 ft-lbs torque. The 200-4R works really well with a 3.08-3.73 rear gear; so does the T5.

I'm up in the middle of the night...but not for long. Check out the build threads in my signature, particularly the Coupe. I also have a discussion on building a non-computer lockup for the 200-4R/700R4 in the 'about' section of my profile. The Wagon has a GN 200-4R. Both cars are parked until I get my life less scattered.
 
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g0thiac

Apprentice
Thread starter
Sep 6, 2020
86
8
Either wil last a long time in a sub 400hp build. Couple of things, if your car has a crazy tall rearend, as most G-'d=s had from the actory. I.e. 2.29, 2.56, etc. and yo intend to keep a short tire, sub 26", then a non OD 4 speed manual will add a gear and function well. The 200-.4R with a .67 OD gear flat out will need a rear gear swap unless you already have swapped the rear and tire size to something lower gear wise and taller tire. The manual will cost more unless you can pickup a functioning used candidate. You can get into a rebuilt 200, converter, TV cable and related parts for under $2k easily.

What is your rear gear and intended tire size?
I honestly don't know the rear end specs, as theres been modifications before I bought it.

It's being stored right now, so when warmer weather starts I can find that information.

And my tires are definitely not short either, they are the big Corvette rally tires, so that is something I do think is worth mentioning.

I'll get you the specific tire size in the month here, currently are stored at my friends place where it's quite easier to access. Thanks for your help.

-Chris.
 

ssn696

Living in the Past
Supporting Member
Jul 19, 2009
4,756
113
Mid-life crisis
Figure out what the wheel bolt pattern is on the Caprice. Most of the big cars came with 5X5, but some came with the G-body 5x4-3/4. Those Chevy Rally rims would look awesome on the Caprice, and the tire size is more appropriate for that car. The 235/60-15 is a nice tire size on a Gbody, and can fit on a 15x7 rim. No shims, no rubbing, no body mods.
 
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g0thiac

Apprentice
Thread starter
Sep 6, 2020
86
8
Figure out what the wheel bolt pattern is on the Caprice. Most of the big cars came with 5X5, but some came with the G-body 5x4-3/4. Those Chevy Rally rims would look awesome on the Caprice, and the tire size is more appropriate for that car. The 235/60-15 is a nice tire size on a Gbody, and can fit on a 15x7 rim. No shims, no rubbing, no body mods.
It's definitely 5x5, and I have been thinking about seeing how they look on the Caprice, when the weather is good enough for me to trust using them.

The Caprice definitely needs work on the suspension and alignments, and the safety, which Ontario does not permit with the use of those wheels.

Once I've dealt with those matters, I'll test the rally's out for sure.
 

Bonnewagon

Geezer
Sep 18, 2009
7,760
113
Queens, NY
As stated, manual trans driving is way better than just sleeping along for the ride. Since it is a 305 there are plenty of G-body parts available to make the swap. Even if you have dead gears out back, there is the later model Saginaw 4 speed trans that has a 3.50 to one first gear. So you multiply that by the rear gear for your overall ratio. The closer to 10 to 1 the better. That is the absolute ideal ratio for easy take-offs without riding the clutch. So the 3.50 times a 2.73 rear gets 9.5 to 1. Pretty close. Times a 3.08 is 10.78- awesome. 3.50 times 2.41 is not so good, 8.4, but you get the idea. This is what GM did before overdrive was common. I myself have that trans with a 3.23 rear, for 11.3 to 1, I use for pulling a boat up the ramp and I can practically climb a tree with these gears.
 
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