I would advise reading a couple of books, especially if hard facts are hard to come by.  There's a book called Chassis Engineering that is very good at explaining all that goes into making a car handle. 

The upper A-arm mod commonly done to early Mustangs (dropping the arm inner pickup point on the chassis) was done to create a better camber curve.  Most streetgoing car suspensions have a lot of compromise built in due to chassis constraints, etc.  When you align a car you set caster, camber, and toe in a static state.  The probelm is that once the car is in motion these specs can go out the window.  The early Mustangs would gain positive camber as the front suspension was loaded.  This reduced the contact patch of the front tires.  Not the hot ticket for a car you want to handle.  Someone figured out that the gain in positive camber was greatly reduced when the upper A-arm mount points to the chassis were lowered.  But, this changed the upper ball joint operating angle which caused them to wear out faster, if not outright bind.  Not a big deal for a race car, but a bear for a daily driver.  The trick was to machine the ball joints to prevent the bind, I think us Mustang guys can now buy ball joints already modified like that. 

However, the camber curve is just part of getting a car to handle.  Things like bump steer, Akerman angle, etc. all come into play.  What we have to choose from now as Mustang guys is incredible.  20 years ago you could do was intall bigger swap bars, poly bushings, and lower those upper A-arms, and that was about the limit unless you wanted to start cutting and welding and had an engineering degree.  It sounds like your T-bird may be in the same boat us Mustang guys were in back then.  So I'd advise understanding everything that goes into suspension work before making any changes.  The simple A-arm drop falls into the category of a little knowledge being a dangerous thing. 

TKOPerformance wrote:

I would advise reading a couple of books, especially if hard facts are hard to come by.  There's a book called Chassis Engineering that is very good at explaining all that goes into making a car handle. 

The upper A-arm mod commonly done to early Mustangs (dropping the arm inner pickup point on the chassis) was done to create a better camber curve.  Most streetgoing car suspensions have a lot of compromise built in due to chassis constraints, etc.  When you align a car you set caster, camber, and toe in a static state.  The probelm is that once the car is in motion these specs can go out the window.  The early Mustangs would gain positive camber as the front suspension was loaded.  This reduced the contact patch of the front tires.  Not the hot ticket for a car you want to handle.  Someone figured out that the gain in positive camber was greatly reduced when the upper A-arm mount points to the chassis were lowered.  But, this changed the upper ball joint operating angle which caused them to wear out faster, if not outright bind.  Not a big deal for a race car, but a bear for a daily driver.  The trick was to machine the ball joints to prevent the bind, I think us Mustang guys can now buy ball joints already modified like that. 

However, the camber curve is just part of getting a car to handle.  Things like bump steer, Akerman angle, etc. all come into play.  What we have to choose from now as Mustang guys is incredible.  20 years ago you could do was intall bigger swap bars, poly bushings, and lower those upper A-arms, and that was about the limit unless you wanted to start cutting and welding and had an engineering degree.  It sounds like your T-bird may be in the same boat us Mustang guys were in back then.  So I'd advise understanding everything that goes into suspension work before making any changes.  The simple A-arm drop falls into the category of a little knowledge being a dangerous thing. 

Thanks TKO thats good info,and you are right about the availabile parts and info guess its too small a niche, Who authored the Chassis engineering book? 

http://www.amazon.com/Chassis-Engineering-Building-Performance-Handling/dp/1557880557/ref=sr_1_1?s=books&ie=UTF8&qid=1419438845&sr=1-1&keywords=chassis+engineering

Yup. Herb Adams, here's a link.  It won't give you specifics, but just as in engine building it helps greatly to understand the theory, especially if you are swimming in somewaht uncharted waters. 

Upon thinking about it, the T-birds must use a totally different suspension setup from the Mustangs because they are body on frame as opoposed to unibody.  That being said I would presume they have their own set of supsension issues, but as 66fastback wisely said you can do a lot with poly bushings, bigger sway bars, and better springs and shocks, all of which should be readily available.  I would also advise a good alignment.  A lot can be done handling wise with a good alignment, though you might sacrifice some in tire wear.  Generally I'd advise running about 1-1.5 degrees of negative camber and as much positive caster as you can dial in.  A smidge of toe in is also helpful (maybe 1/16-1/8" total).  Cars of this vintage tend to have bad camber curves, so a bit of static negative camber helps reduce the affect of camber gain.  They also have 0 caster to negative caster, which makes high speed handling dicey and increases wander on the highway.  The trend at the time was to have one finger steering effort, not NASCAR handling.  You have to be a bit careful if you have manual steering as too much positive caster can make turning it a feat for Schwatzenegger, but with power steering you should be fine.  You'll be adjustment limited anyway, just get as much as you can positve.  A little toe in helps to keep the car straight during higher speeds and stable during heavy braking.  Its also an area to experiment, because short track guys tend to run toe out because it improves turn in on corner entry.  But that's best suited a a twisty track or SCCA course, not so much DD duty. 

TKOPerformance wrote:

http://www.amazon.com/Chassis-Engineering-Building-Performance-Handling/dp/1557880557/ref=sr_1_1?s=books&ie=UTF8&qid=1419438845&sr=1-1&keywords=chassis+engineering

Yup. Herb Adams, here's a link.  It won't give you specifics, but just as in engine building it helps greatly to understand the theory, especially if you are swimming in somewaht uncharted waters. 

Upon thinking about it, the T-birds must use a totally different suspension setup from the Mustangs because they are body on frame as opoposed to unibody.  That being said I would presume they have their own set of supsension issues, but as 66fastback wisely said you can do a lot with poly bushings, bigger sway bars, and better springs and shocks, all of which should be readily available.  I would also advise a good alignment.  A lot can be done handling wise with a good alignment, though you might sacrifice some in tire wear.  Generally I'd advise running about 1-1.5 degrees of negative camber and as much positive caster as you can dial in.  A smidge of toe in is also helpful (maybe 1/16-1/8" total).  Cars of this vintage tend to have bad camber curves, so a bit of static negative camber helps reduce the affect of camber gain.  They also have 0 caster to negative caster, which makes high speed handling dicey and increases wander on the highway.  The trend at the time was to have one finger steering effort, not NASCAR handling.  You have to be a bit careful if you have manual steering as too much positive caster can make turning it a feat for Schwatzenegger, but with power steering you should be fine.  You'll be adjustment limited anyway, just get as much as you can positve.  A little toe in helps to keep the car straight during higher speeds and stable during heavy braking.  Its also an area to experiment, because short track guys tend to run toe out because it improves turn in on corner entry.  But that's best suited a a twisty track or SCCA course, not so much DD duty. 

OK I'lll start reading. But this is a unibody though with much heavier contstrction but exactly the same configuration as the 'stang and in answer to Barnett not to offend but a Caddy rides like a pulpwood truck compared to these cars. very low very heavy one finger steering so easy that oversteer is the norm,it literally steers like a speed boat, unless your used to it you are constantly correcting, since I built the engine its a lot more noticable I'd reduce steering pump pressure with a regulator but it also feeds the hydraulic windsheild wipers. 

barnett468 wrote:

well i actually know exactly what an old caddy and old tbirds ride like . . i sold my 63 convert bird a few years ago . . i was just trying to point out that it will no longer be as soft . . also, reducing the steering pump pressure will NOT reduce the affect you are feeling but do it of you want to.

if your steering is overly sensitive then either your control valve is bad or your front end alignment is incorrect because they were not overly sensitive from the factory . . also, your alignmrent is supposed to have negative caster which can cause this feeling more than positive camber, so you could also try running around 1 1/2 degreews of positive caster but the steering might feel a bit heavier.
.

 

Thanks I will add a little positive caster and note the results, I've driven a few old caddys and lincolns too they just don't glide like the Birds guess i'm fickle.