There’s been a discussion off and on about using Aerostar springs. I just finished that on the 55 bird and this is the results.



55 Thunderbird, p/s p/b p/w p/s and SN2000 Paxton to add weight.

Headers, alum front cover, and Blue Thunder to deduct weight.

I haven’t weighed the car, sorry.



Removed springs 14 ¾ inch free height

One end square, one end Tangential

8 ¼ turns, counting the flattened part of the Tangential end.



I assume these were stock, but I can’t remember if we cut them slightly after the manifold and headers went on.



New springs, NAPA 2775245. 1992 Aerostar

Free height 11.65”

One end square, one end Tangential

Load height (Aerostar) 10”

Design load 997 (presume lbs)

Rate 605 (presume lbs/in)

Variable rate coil



About $85 with shipping from So Cal to Seattle



The front fender lip, from ground on wheel center, 24 7/8 right, 25 1/8 left. Stock replacement 15” Coker radials.

This is ½ inch higher than before.



I put stiffer shocks on, but can probably use more. The car rides a little harder, but better, and way better in a corner or a large bump. I assume this is due to the variable/higher rate.



Driven maybe 65 miles, and sitting 3 weeks, there has been no noticeable settlement.



I got a set of Mummert’s heads last week, and after they’re on, I’ll put some miles on it and cut (probably the square end) to lower the front ½ inch from the current height and even it out with me in the seat. I liked it there. While the ride was expected to be better, I was concerned it was going to lower the car too much. Didn’t happen. Don’t know the difference between a ‘bird and full size car, but I’d be surprised if it pushed it down 2 1/2 inches more.




miker
55 bird, 32 cabrio F code
Kent, WA
Tucson, AZ