Lowering my 69

Smash It Up · Oct 29, 2007

I would like to lower the front and stiffen up the rear of my 69FB.
I want to make it at least level,or maybe have ther rear slightly higher than the front,and stiffen up the rear because every time I go over a bump or dip,the rear end comes down with a thud,its way too soft,and makes me cringe each time !
I want it so that there's not much give.
As far as the front goes,can I just change out the springs on each side for ones that are an inch,maybe 2 inches lower. What about the current shocks? Would they have to be changed along with the springs?
For the rear,would I just need to change the shocks,or do the leaf springs too? I'm not sure if the leaf springs are original or not.

Any recommendations or things that might help me out?

thanks

DK832 · Oct 29, 2007

Get some "620" front springs with lowering like these:
http://www.mustangsplus.com/xcart/product.php?productid=1038&cat=2128&page=1
They will only give you 1" drop so a Shelby mod is also in order.

Rear without much give at all means a 5-leaf setup like:
http://www.mustangsplus.com/xcart/product.php?productid=1018&cat=2124&page=1
5-leafs should go with stiffer fronts than 620 though IMHO...

bnickel · Oct 29, 2007

i'm running 5 leafs mid-eye leaf springs with KYB GR-2 shocks in the rear and 750 1" drop coils up front with Opentracker roller spring perches and KYB gas-adjust shocks up front. with the 351w, ac, ps and heavy FMX auto trans the suspension in the car is actually not harsh at all and rides pretty well, though if you hit some really good bumps it can get pretty stiff. altogether, though, it's not bad like most people think it would be. the car sits almost perfectly level, it's exactly 1/2" higher in the rear.

Smash It Up · Oct 29, 2007

DK832 said:
Get some "620" front springs with lowering like these:
http://www.mustangsplus.com/xcart/product.php?productid=1038&cat=2128&page=1
They will only give you 1" drop so a Shelby mod is also in order.

Rear without much give at all means a 5-leaf setup like:
http://www.mustangsplus.com/xcart/product.php?productid=1018&cat=2124&page=1
5-leafs should go with stiffer fronts than 620 though IMHO...

Like these?
http://www.mustangsplus.com/xcart/product.php?productid=1030&cat=2128&page=1
Although it does say that they are very stiff which is uncomfortable for most normal street driving applications.

And I'm not sure exactly what you mean about the Shelby mod,what does that entail?

Smash It Up · Oct 29, 2007

Thanks for the replies.
I just checked the rear shocks,and they are Monroe #31069's.Cheap. And the ones on the front don't even have a name on them.!!
So I think anything will be an improvement on those,so how about this combination.:

5 leaf mid or reverse eye springs
Grab-A-Trak 750 Front Coil Springs (cut as neccessary to suit height)
KYB Gas-A-Just shocks all round

$412 total to upgrade the whole damn thing,I can afford that,I don't want to spend tons of money,but that's in my range,and I can do 90% of the work on my own. Might need an extra pair of hands here and there.

CochinoFilipino · Oct 29, 2007

As a spring wears out the spring rate remains the same. Unless they are too soft or too stiff for you I'd just cut a coil from the front springs. Cutting coils will also increase the spring rate.

For the rear, I'd just replace the shocks first and see if that fixes your problem.

180 Out · Oct 29, 2007

Do not use 720 lb springs. Much too stiff. I like Cochino's advice: cut the coils and put some KYB Gas-A-Justs at all four corners. This will solve the stance problem and most likely the bottoming out problem. The Shelby drop is also a good mod for handling. Do that while you have the coils out. Then see how you like the ride and handling. If you want more roll stiffness a 1" sway bar is a good idea.

bnickel · Oct 29, 2007

180 Out said:
Do not use 720 lb springs. Much too stiff. I like Cochino's advice: cut the coils and put some KYB Gas-A-Justs at all four corners. This will solve the stance problem and most likely the bottoming out problem. The Shelby drop is also a good mod for handling. Do that while you have the coils out. Then see how you like the ride and handling. If you want more roll stiffness a 1" sway bar is a good idea.

why do you say that? i have the 750 coils and it is not the least bit harsh. granted i have Opentracker roller perches on it right now but previously i had stock rubber bushed perches and used regular old monroe matic shocks and it still wasn't the least bit harsh. it all depends on how much weight is in the front end, if it has an iron block 351 or larger with AC and power steering like mine has it rides just fine and i honestly wouldn't run a softer spring on my car.

CochinoFilipino · Oct 29, 2007

bnickel said:
i'm running 5 leafs mid-eye leaf springs with KYB GR-2 shocks in the rear and 750 1" drop coils up front with Opentracker roller spring perches and KYB gas-adjust shocks up front. with the 351w, ac, ps and heavy FMX auto trans the suspension in the car is actually not harsh at all and rides pretty well, though if you hit some really good bumps it can get pretty stiff. altogether, though, it's not bad like most people think it would be. the car sits almost perfectly level, it's exactly 1/2" higher in the rear.

Just highlighting some important points to consider, especially if he cuts coils and make the 750s even more stiff

Smash It Up · Oct 29, 2007

Yeah I think I get what you mean. Instead of spending out for new coils and cutting them,just cut the ones I have now to make it a bit stiffer.

I think what I'll do first is get the KYB Gas-a-Just shocks all round,see how that goes,and then decide if I need to cut the front coils down and change the leaf springs on the back.

Like I said before,it has to improve on the cheapo shocks that are already there,LOL

bnickel · Oct 29, 2007

CochinoFilipino said:
Just highlighting some important points to consider, especially if he cuts coils and make the 750s even more stiff

read this post again. and i don't the GR-2 shocks on the front, they're on the rear, i have the regular KYB's up front.

CochinoFilipino · Oct 29, 2007

bnickel said:
read this post again. and i don't the GR-2 shocks on the front, they're on the rear, i have the regular KYB's up front.

Understood, but his outline stated regular KYBs all the way around. I was just highlighting some things that he may want to take into consideration.

Smash It Up, What engine and trans do you have?

CochinoFilipino · Oct 29, 2007

Smash It Up said:
Yeah I think I get what you mean. Instead of spending out for new coils and cutting them,just cut the ones I have now to make it a bit stiffer.

I think what I'll do first is get the KYB Gas-a-Just shocks all round,see how that goes,and then decide if I need to cut the front coils down and change the leaf springs on the back.

Like I said before,it has to improve on the cheapo shocks that are already there,LOL

I had regular KYBs all the way around in a '71 350/350TH Camaro and hated them out back. Not sure how that translates to Mustangland but I probably won't be using them out-back on anything again

bnickel · Oct 29, 2007

CochinoFilipino said:
Understood, but his outline stated regular KYBs all the way around. I was just highlighting some things that he may want to take into consideration.

Smash It Up, What engine and trans do you have?

ok, i gotcha. yeah with the gas-adjusts up front it might be a bit harsher.

DK832 · Oct 30, 2007

Ever tried the progressives?
http://www.mustangsplus.com/xcart/product.php?productid=3179&cat=2128&page=1

I'm seeing a qouple of choices for replacing my weak 620 fronts to match the 5-leafs in the rear:
1) 750 with Opentracker roller perch
2) Progressive (above) with roller perch
3) Ron Morris ETI Shock Kit (see http://www.ronmorrisperformance.com...mp&Product_Code=5160&Category_Code=Susp_Parts )

Hmmm....

69gmachine · Oct 30, 2007

bnickel said:
i'm running 5 leafs mid-eye leaf springs with KYB GR-2 shocks in the rear and 750 1" drop coils up front with Opentracker roller spring perches and KYB gas-adjust shocks up front. with the 351w, ac, ps and heavy FMX auto trans the suspension in the car is actually not harsh at all and rides pretty well, though if you hit some really good bumps it can get pretty stiff. altogether, though, it's not bad like most people think it would be. the car sits almost perfectly level, it's exactly 1/2" higher in the rear.

I think the key to why bnickel is so satisfied with his combination is that it's so heavy. Assuming he has a stock iron PS pump, the very heavy iron FMX, stock AC system, guessing iron heads on the Windsor, the very stiff springs and shocks are OK. I have taken a lot of weight off the front end with aluminum heads, water pump, intake, battery moved to trunk, late model PS pump, etc. Before I switched to the coilover set up, I had gas-adjusts on all 4 corners and Eibach progressive rate springs. I still felt the ride was too harsh. If your car is loaded with stock options, the combo you mention will probably be fine, but if it's much lighter, I'd go with the GR-2s all around and less stiff springs up front.

bnickel · Oct 30, 2007

69gmachine said:
I think the key to why bnickel is so satisfied with his combination is that it's so heavy. Assuming he has a stock iron PS pump, the very heavy iron FMX, stock AC system, guessing iron heads on the Windsor, the very stiff springs and shocks are OK. I have taken a lot of weight off the front end with aluminum heads, water pump, intake, battery moved to trunk, late model PS pump, etc. Before I switched to the coilover set up, I had gas-adjusts on all 4 corners and Eibach progressive rate springs. I still felt the ride was too harsh. If your car is loaded with stock options, the combo you mention will probably be fine, but if it's much lighter, I'd go with the GR-2s all around and less stiff springs up front.

exactly my point, if the car is stock and has all the options then the 750 coils work just fine and aren't too stiff. my point was that it all depends on what car you have and what options it has as to which springs to use, i hear people saying all the time that the 750's are way to stiff for a street car but that's not necessarily the case. for my car, the way it is now, i wouldn't run a softer spring than what's on it now otherwise the car would bottom out over every bump in the road. yes the roller perches soften it some but even with stock perches and monroe shocks the ride has never been harsh. i'd guess that the 750's and GR-2's with stock perches would be about the same. BTW, i do have an aluminum intake and headers so it's not quite as heavy as 100% stock

for a 302 car or even a 351 car with less options the 750's might be too stiff but for a 351 car with lots of options or a big block car the 750's are just fine. there is more to picking a spring than what a couple guys on the 'net say to run, that's all i'm saying. YOU need to research which springs would be best for your application. i even hear guys with 65-65 cars with 289's and 5 speeds saying that the 620's are too harsh but their cars' are the ones with aluminum heads and only an alternator on the front end, so when they say their 620's are too harsh and i can understand why, but the exact same car with iron heads, power steering and AC might like the 620's just fine.

ok, to the point. if someone asks for a spring recommendation we need to know more about the car than just the year, but pretty much any 69/70 wil need at least a 620 spring or higher because the 69's are quite a bit heavier than a 65-66 or even a 67-68 car.

bnickel · Oct 30, 2007

so smash it up tell us more about your car and be specific about the options it has, also tell us what else you plan on doing to the car.

Smash It Up · Nov 5, 2007

OK,just got a set of Gas-a-Just shocks and did the front ones today. Much better is all I can say. And thats before i even got to the rear ones yet !!
I took it out for a spin and did some pretty speedy cornering let me tell you.and this sucker actually feels better,less rolling etc.
the shocks that were on the front were crap,the drivers side one could be squeezed closed with my hands easily,although the pass side one was better. ( The springs still need to be worked on though,I'll be getting a spring compressor and hacking a bit off those babys. )
Next project is the shocks on the back,at the moment it sags and bottoms out every bump or dip (crappy $15 Monroe shocks!!) and see how that helps. Probably will help some,but I still like the idea of getting the 5 leaf springs on there and stiffen that sucker up at the back.
I don't mind a firm ride,as long as its not totally jarring. Its not like I drive hundreds of miles in it,its just my fun-burn-some-rubber car.
My neighbour said to me today "Anytime you want me to take it for a test drive,you let me know" , I said ,ok I'll get back to you on that. Anyhoo,I digress.

For those who asked,the enige is a 351w with a FMX tranny.

And one question,does the rear shocks poke up through the floor under the rear seat,is that where the nut is? I'm sure I saw it there when I had gutted the interior,but wanted to make sure before I go tearing out the back seat !!

DK832 · Nov 5, 2007

Smash It Up said:
And one question,does the rear shocks poke up through the floor under the rear seat,is that where the nut is? I'm sure I saw it there when I had gutted the interior,but wanted to make sure before I go tearing out the back seat !!

There are 2 oval rubber grommets in the trunk about 1' behing the back of the seat. The top of the shocks are underneath.

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