MikeStang 247 Report post Posted August 3, 2016 Oh and I drag my header collectors on Everything and I have FPA headers so they fit tight to the floor... have about 3" of ground clearance on headers and I knocked a hole in my trans pan last week LOL...So keep that in mind Quote Share this post Link to post Share on other sites
schweigert 13 Report post Posted August 3, 2016 So I ended up cutting a half coil - and overall its a 1" drop. probably cut another half coil in a bit. - i'll post a pic laterthe ground to top of outer wheel well curve is 27" in the front, and 26" in the rear - so front is still sticking up a bit. i'm a little confused though - 620 springs = shelby drop springs? I thought they were their own spring? Quote Share this post Link to post Share on other sites
MikeStang 247 Report post Posted August 3, 2016 not sure about the Shelby drop springs but the 620's and 550's are just the coil spring weights...higher weight made to support heavier load etc... Quote Share this post Link to post Share on other sites
larryc94 38 Report post Posted August 4, 2016 620's is the wire size they are 560 lb Larry Quote Share this post Link to post Share on other sites
larryc94 38 Report post Posted August 4, 2016 I can't believe that I haven't run across some using the combo I have on a '67-'70. I have 620 springs for a '65-'66 (happen to be Graba-trac's, don't think that matters) they are 1" lower than the '67-'70 with 3/4" poly spacers. The spring are 1" lower than the '67-'70 620's, so the 620's are 1" lower and by going with the '65-'66 620 it is an addition 1' for a total of 2'. I have read that most everyone cuts the 620's to get the stance they are locking for.. So why not start out with a spring that was designed to be lower. The springs are uncut, that's a thing that i don't believe in...yea I know every one cut's them but you alter the rate of the spring. I have roller perches with an otherwise stock front end. New bushings etc, Ford export brace, monte bar and I know hold the flames KYB Gr2's. But I can take speed bumps pretty good, maybe 10 mph and the front end just sucks them up, can't say that for rear but. The rear I have Scott Drake 4 1/2 mid eye's with 1" blocks. I was afraid to go to reverse eye's for fear of being too low and not being able to correct it except for changing springs. If it get's too low I can always pull the blocks. I do have the front of the spring pack clamped a la the '60 MOPAR thing to eliminate wheel hop I was getting. They were good new but after I while I think the clamp opened up and let the spring start to move and create the wrap-wheel hop. I think the clamp stiffens up the rear spring but have no wheel hop. This combo yields a great ride on our chopped up Northeast roads. When I did it I didn't know how it was going to turn out, well too my surprise it works well. I guess every now and again we luck out. Quote Share this post Link to post Share on other sites
schweigert 13 Report post Posted August 4, 2016 I can't believe that I haven't run across some using the combo I have on a '67-'70. I have 620 springs for a '65-'66 (happen to be Graba-trac's, don't think that matters) they are 1" lower than the '67-'70 with 3/4" poly spacers. The spring are 1" lower than the '67-'70 620's, so the 620's are 1" lower and by going with the '65-'66 620 it is an addition 1' for a total of 2'. I have read that most everyone cuts the 620's to get the stance they are locking for.. So why not start out with a spring that was designed to be lower. interesting - so I have this kit https://www.mustangsplus.com/1967-1968-1969-1970-Mustang-Spring-And-Sway-Bar-Kit-Grab-A-Trak-R.html - you're saying if i got the 65 kit instead - the 620 springs are different - and would be 1" lower than the ones i got? Quote Share this post Link to post Share on other sites
larryc94 38 Report post Posted August 4, 2016 What I'm saying is the 65-66 spring is identical to to 67-70 spring except the free height is 1' shorter. Same diameter, same 560 lb rated spring. I seen posts where guys cut the 620's and say the ride stiff and feel every bump in the road. Mine is very smooth and the suspension just absorbs the bumps. The other thing is it's low but not low enough to cause problems, no bump steer, not bottoming out etc. Forgot have the Shelby drop and think the roller perches contribute to the good ride by allowing the springs and shocks work without bind. The other thing I had when first installed the 65-66 spring with 1/4 poly spacer was the spring would get loose jacking the car up, I couldn't deal with that every time I put it on the lift was to make sure the springs were seated (this ain't no Honda). Also it was lower, maybe too low. But with a 3/4 poly spacer it's just right, spring has tension on the lift and doesn't move Larry Quote Share this post Link to post Share on other sites
MikeStang 247 Report post Posted August 8, 2016 Yeah that is the crappy part of cutting the spring height, it makes it so the springs practically fall out when you put the front in the air Quote Share this post Link to post Share on other sites
