drewsky

Im trying to decide if i should leave the springs already in the 67 which are already pretty stiff... or put the 620 grab-a-trac in. I already have the 620's but have heard they are just waaaay too stiff. all thoughts will be appreciated.

P.S. I have been a member of these forums for quite some time and read them reguarly. I am finally making headway on my 67 coupe and will keep all of you posted with pics and progress, with ?'s along the way. i am really glad to see the classic section jump in members, years ago there was mabe 1 or 2 ppl looking at once. Now evrytime i go on there is 30+ viewing!

greystallion66

I have 620's in my 66 with 5 leaf rear springs. I do not think it is too stiff, then again I like my car to ride firm down the road. I think it is a personal preference. You can always buy them, if they are too stiff sell them and buy some other ones. I say go for it!!!!

Norm Peterson

A firm ride that comes from stiff springs does not have to be harsh. A harsh ride usually comes from the shocks.


Norm

Starfury

I have 540's, roller perches, and Edelbrock shocks which are smoother than KYB Gas-A-Justs. I wouldn't want 620's where I drive. The roads here suck, and I have a hard enough time keeping the tires on the road as it is. Plus, my 540's work great for hard driving.

Keep in mind, roller perches will help smooth out the ride.

Jonk67

Agree with Norm, your shocks will control rebound but too stiff a spring can give you a stiff 'wagon wheel' ride also. What shocks are you using?
I installed 1" drop 560 springs, 4 1/2 leaf mideyes and KYB GR-2's all around (will upgrade when my driving skills and wallet agree) and the ride is comfortable but responsive. I haven't taken my car on a road course yet and still have the stock skinny sway bar up front so I don't know how much flex I'll have yet. Does well on the twisty hills of TN though.
Just like motor components you need to match your suspension parts up and things like the 1" Shelby/Arning drop and roller perches all allow your suspension/steering to perform at it's best.
Jon

drewsky

I have heard about the roller perches and was planning on installing them as well. but have been debating just cause of price, so how much do they really help? is it worth the extra $? I have kyb gas a just all around. (the grab a track kit). it seemed great before purchase but looks like cheap components when they arrived. i know the 620's lower the front end and thats what turned me onto it more...... so get some new springs that lower the front along with roller spring perches or just roll with what i have now? i pan on driving through the town and occasional hwy, but not daily driven.

Norm Peterson

Any time you can eliminate some friction/stiction in your suspension, ride quality will improve.

Since KYB GAJ's already tend to be a little on the harsh side (I've had them on other cars), I think it would be a good move to eliminate any other source of harshness. I'm NOT saying that a car with GAJ's will handle poorly here, actually they seem pretty decent in that respect. It's just that their behavior over rough bumps is a bit stiffer than necessary.


Norm

JamesW

Agree with above. I have 620s with GR-2s and the ride is not harsh at all. It's the shocks that make the ride unconfortable.

Starfury

My concern with running GR-2's with 620's would be that they don't provide enough damping for the stiffer springs. I don't have a car set up like that, but if that's the case, you'd end up with a car that bounced more than necessary after large bumps.

How's your car in that respect, James? If you go over a rise in the road at speed and come down on the suspension, does it keep bouncing up and down?

67mustang302

It depends on how much performance you want and how much ride quality you want. They generally don't go hand in hand. Better performance will always sacrifice ride quality to some degree, some technology can improve that such as roller perches, but you'll never get a Cadillac ride with Ferrari performance. A stiffer shock will dampen better and provide better performance, but at the same time doesn't allow for quite as much suspension motion, so the energy gets transferred into the chassis and the ride quality drops. Some people like a stiffer ride, and personally I like to feel the road, other people prefer a softer ride. Shock and spring choice is to some degree a matter of personal preference, it comes down to how much you care about ride comfort vs how much you care about handling performance.