Transmission upgrade?

[Polishmeatballpizza]

I presume most here have gone to the 700r trans, vs the power glide? Any changes to the rear differential required?

[GS66]

Mine still have the 2 speed and one has a Turbo 400, no overdrive here. That's a great upgrade though! So are disc brakes.

[dsags]

Standard rear axle ratio in a Powerglide is 3.08. That's probably not a great gear for a 700r4. The overdrive would be a 2.16 ratio at 70% OD.

[elagache]

Dear George, Jim, Dan, and mid-60s Buick gear changer experts

I presume most here have gone to the 700r trans, vs the power glide? Any changes to the rear differential required?

You have a Buick 300 engine in your Special (unless you decide to change that.)  In that case, the GM 200-4R is a slightly easier swap.  The 200-4R will bolt directly to your engine while a 700-R4 needs an adapter.  If you stick to the 300 cid, you could probably get a stock 200-4R.  210 horsepower isn't sufficient to overload that tranny (any counter opinions?)  The 200-4R should not require any changes to the drive shaft or the rear end ratio (unless you want to change the rear end for better performance.)

My wagon has a slightly more assertive engine!



In such cases you would need a hardened 200-4R.  There is a lot of guys who go with the 200-4R and many others who prefer the 700-R4.  In the Buick world it seems to be about 50/50.

Are you planning to stick with the stock engine?

Curious minds want to know!

Cheers, Edouard 

P.S. I jumped the gun and assumed you wanted overdrive.  Actually the ST-300 is a very nice transmission if you don't overdrive.  There are also other ways to get overdrive with older transmission.  When it comes to classic cars, there are lots of ways to skin a cat(fish!)

[Polishmeatballpizza]

I am really not sure which way to go.  My trans, I presume is a two-speed, will need a rebuild. That will probably cost me $1200. I always heard the overdrive transmissions were the way to go.  If I need to change my rear diff ratio to accommodate a 700r or 200r, I may be better off sticking with the two speed? I have no experience this car as a driver,  so I need some education and experienced opinions.

[GreatScat1965]

I guess it is all about what you are ultimately looking for. Frist $1200. to rebuild your trans is going to be a lot cheaper than a trans swap once you figure in all the "little extras". Assuming you want overdrive as an upgrade I agree the 200R4 is the way to go. They can handle a Grand Nationals power I think you will be fine. As for the rear end ratio, the 200R4 has a 2.74:1 first gear and the ST300 you have only has a 1.76:1. So there really is no need to change the rear end gears. A mid 80's Regal would have come with a 200R4 and either a 2.73 or 3.08 gear with the V-6.

This would be a good time to have the driveshaft balanced and put new u-joints in it.

I have a ST400 converted to fixed stall behind my Nailhead with a 4.11:1 gear ratio. That's not for everyone for sure. I like the late 60's early 70,s style muscle car  feel. I drive to all summer but I prefer to stay off the interstates. There's more than one way to a cruise night. I like the back roads and barking the tires between gears. It's "car music" to me.

Jerry

[WkillGS]

I still have 4.11's in my blue '66..... been in there since 1982! Did lots of highway trips back then, but it was at 60-65 mph. Today's sustained 75-80 mph highway speeds are not an option.

For the 300 engine, a TH350 would be another option. No overdrive, but has a lower first gear. Very plentiful and you could likely find a decent one to swap in.

The original ST300 does have the benefit of the 'switch-pitch' converter..... switchable between a performance high-stall and the low stall economy mode.  Again, you could likely find a decent one to swap in that doesn't need a rebuild.

Yet another option is a manual trans 5 speed. More fun than any automatic!
For my '66 Special with 300 engine, I used the bellhousing, linkage and pedals from a V6 car, flywheel from a 350, and a Richmond 5 speed trans I got for $1500.

Unless you do lots of high speed highway driving, you don't 'have' to install an overdrive.

[Polishmeatballpizza]

Like GreatScat1965 said, maybe 1200 for a rebuild isn't that bad. I'm not dead-set on upgrading to overdrive, I just thought it was an easy upgrade. I saw some local CL ads for a 700r for $400-$800, rebuilt (local tranny shops).
Maybe I can find a rebuiltime trans for my car. The stock trans in this buick is an ST300?

Has anyone rebuilt the ST300? Is it very difficult? Something I should consider doing?

[GS66]

I had one rebuilt in my 66, was $1300 at a transmission shop in town. I must say its never worked better than it does now.

[GreatScat1965]

Like GreatScat1965 said, maybe 1200 for a rebuild isn't that bad. I'm not dead-set on upgrading to overdrive, I just thought it was an easy upgrade. I saw some local CL ads for a 700r for $400-$800, rebuilt (local tranny shops).
Maybe I can find a rebuiltime trans for my car. The stock trans in this buick is an ST300?

Has anyone rebuilt the ST300? Is it very difficult? Something I should consider doing?

If it has a switch pitch converter it is an ST300 (Super Turbine) Basically a PowerGlide with a unique converter set up. Does the rebuilt trans come with a torque converter for the $400-800. price? Your converter will not work in a 200R4.

Jerry

[sjfd04]

Just converted my car to a 4 speed manual, bought the entire setup from Brian.  I have my rebuild ST 300 available if you would like to go that way.  I'm in Northern California if you want to pay to ship it.  400.00, everything.

[Polishmeatballpizza]

Just converted my car to a 4 speed manual, bought the entire setup from Brian.  I have my rebuild ST 300 available if you would like to go that way.  I'm in Northern California if you want to pay to ship it.  400.00, everything.

Rebuilt? Ready to go?

[sjfd04]

Yes Sir, does need fluid. 

[WkillGS]

If that trans is from a GS 401, it won't bolt up to a 300 engine.
There was an adapter to use a Nailhead ST400 trans behind a 350 Buick engine on certain Jeeps in the late 70's. Might work in this case.

[Polishmeatballpizza]

If that trans is from a GS 401, it won't bolt up to a 300 engine.
There was an adapter to use a Nailhead ST400 trans behind a 350 Buick engine on certain Jeeps in the late 70's. Might work in this case.

Damn - it won't work?