4.1 NA Buick Regal

[BUICKTR]

I just bought a 1983 Buick Regal Limited with original 24K miles on it. My question is what size of rear end, gear ratio and transmission are on these cars? I'll appreciate it.

 

[Silver 6]

Its real hard to say without seeing your car, but...

The 7.5" rear with a 2.41 gearset would likely be the base unit.

The transmission is a hard one because there were so many choices. This was the first year the TH200R4 four speed auto was available in the Regal. You could also have a TH200C or a TH350C under there if it is a three speed. They both use the same kickdown cable, so you would have to take a look.

 

[BUICKTR]

Silver 6

Thanks for the info! I want to know more on the trans and rear end because I want to upgrade the gears in the rear end. I'm thinking of putting in 3.08 or 3.23 gears. The car runs great on the highway and once it gets rolling, but from the dead stop it is a little sluggish so I figure changing gears might help it out. Now I know why we need a turbo on these V6's. I know for a fact I don't have an overdrive gear. Just has 3 speed with TV kickdown cable.

 

[Silver 6]

There is a good chance your car came with the TH200C. This was looked down on by most people because it was believed to be a weak trans. We now know it was the heart of the trans used in the turbo cars. Many of the same parts used to improve the four speed will go into the three speed. The 200 model trans has a lower first gear, 2.74 than the 350 model with a 2.52.

You could also looking at adding some stall speed to the converter in the trans. If it is the 200 model, it will use the same converter as the four speed 200R4. There are many out there would allow you some additional RPM for starting out, but allow you to keep your rear gears for the economy when the converter locks up.

 

[turbofish38]

I've had in my possession at one time 2 83 4.1NA Regals and assuming you have a 3-speed auto it should be a THM350C. An easy way to tell is the 350C has a seperate tailshaft extension with a vacuum modulator and the 200C has a one piece case with no vacuum modulator. The standard ratio with the 350C auto is 2.41. If it has the 200-4R OD than the ratio could be a 2.73 or 3.08.

A side note on the TV cable. 200C and 350C cables are not interchangable as they have different diameter of mountings where they attach to the trans case.

The 200C is an excellent transmission for a NA as they are lighter than the 350C and there are lots of HD parts for them now. Many Stock/Super Stock drag racers that run V-6 and 4 cylinder engines prefer them for this reason.

 

[Silver 6]

The 200C is a great little trans if set up properly. Along with that low first gear it also takes the least horsepower to run. That means either more power to the rear wheels, or better MPG.

I keep giving thought to putting one in my 79 Sport Coupe.