progress springs

Discussion in 'Classic Mustang Specific Tech' started by vrooom, May 23, 2003.


    Is anyone running Progressive rate front coil springs? How would you rate and/or compare these to 620 springs? (ride, performance, etc)

    Any thoughts or opinions appreciated.

  2. Don't have them but I saw those after I had purchased my 620's. If I'd seen those first, I would definitely have bought them instead. I wanted the stiffness for handling, but it isn't very practical for ALL driving. I would love a smoother ride over these crappy roads, railroad tracks, potholes,etc...
  3. Yea,... I'm really leaning toward doing that as well.
    Removing the 620s for part of the year
  4. progressive springs

    WHich ones would be a good combination for a 351w, 1" sway bar, TCP uppers, boxed lowers and 4 leaf rears w/ 3/4" adjustable sway. Edlebroock Shocks?

    390 to 520 or the 460 to 600 ?

    67/73 SMALL AND INTERMEDIATE BLOCK, 390 TO 520 lbs/in . . . . . . . . $159.95
    67/73 BIG BLOCK, 460 to 600 lbs/in . . . . . . . . $159.95
  5. I am using the big block 600's in mine. the ride is alittle stiff a lower speeds but the handling is great. at higher speeds it smooths out on the ride and doesnot give you that boat in the water floating bounce.
  6. what engine do you have? Do you think the small block ones would be too light for a 351w?
  7. In my 69, with 351w I'm running the
    67/73 SMALL AND INTERMEDIATE BLOCK, 390 TO 520 lbs/in

    I LIKE EM!:nice:

    I've got the TCP subs and x-brace, 1 1/8" sway bar with all polygraphite bushings from PST, and the 17" wheels - and it goes through turns sooo nicely.. I haven't done any hard turns over 40 because the back tires start to rub. If your car is mostly street, I don't think you can go wrong. I compensated by getting the bigger sway bar - this way going straight I can get a little more cushion, and when I get into the turns, I figure I'll let the sway bar do its job.
  8. Totally agree... get the 390-520lb ones...they call them small and intermediate block springs for a reason :p
  9. update info needed

    I know I started this thread last May, but am hoping more people have install the progressive rated springs since.

    I plan on running these with GW uppers and not TCP now. If you have any new feedback please post. Also would like to know which rear springs you are running and how you like your setup.

    Thank you.

  10. Yes. I have since installed them. I'm very pleased.
    TCP uppers/lowers/strut rods.
    Rear is 5 leaf. They are fine. I ripped the spring perches from the rear axle
    a few months ago when I ran ET Streets, and have since re-welded and gusseted them. The 5 leafs held up just fine.