think it's a little lower than stock. I took ride height measurements before I started the project. I measured from the floor to the top center of the wheel openings front and rear
Measuring from body parts is of no use, as suspension has to be set relative to its components, in relation to floor. Body parts are not consistently mounted, and are aligned to mate with their neighbor, not suspension parts. These cars don’t have close build tolerances.
Per Factory Service manual:
Front suspension heights must be held to specification for a satisfactory ride, correct appearance (this subjective to today’s eye), proper front wheel alignment and reduced tire wear,
First vehicle has to have full tank of fuel, no passengers, no luggage in trunk excepting spare tire & jack, properly inflated tires, and on sitting on level floor.
Clean all crud from lowest portion of steering knuckle arm, and height adjustment blades directly below lower control arm inner pivots.
Jounce front of vehicle several times releasing it on a downward motion.
Measure from lowest point of adjusting blade to floor (measurement A), and from lowest point of steering knuckle arm to floor (measurement B); measure only one side at a time.
Subtract distance A from B and adjust height by big bolt in center of LCA adjusting as necessary until A-B= 2 ½” +/- 1/8th inch. Per 1967 A Body height spec for both standard & HD suspension; I suspect it is the same for a 1968 & 69 A bodies.
After every adjustment jounce front end before remeasuring. Both sides should be measured even though one side was adjusted. Adjust other side.
Ping pong left to right making adjustments until each side is within 1/8th inch of the other.
I think maybe the leaf springs were HD for a 340 so the rear may be a little higher
I’m not fluent in ’69 340 rear suspension, but suspect it is identical to S Cuda set-up which I believe used a six lief factory ride height rear spring. Even though a six lief spring was used, it was not significantly stiffer than stock springs, but provided better axel control under hard acceleration.
Your choice of one inch torsion bars is a good one; these cars left the factory with mushy low spring rates on the front end compared to today’s cars. GM and Ford’s suspensions were even sloppier than Mopar’s in the day providing almost no suspension control, they were simply dreadful wallowing hogs.
I have fitted six lief stock ride height rear springs to My Dart rag top with an 8 3/4th inch rear, with 0.940” torsion bars all at factory ride height, and car handles neutrally with a well behaved rear axle.
Rear spring ride height changes in one inch increments are available if one desires a slight lift of rear end. As rear of an A body over stock ride height increases, the more tail happy (tendency to over steer) it will become.
Call Spring N Things… ESPO for the details, A body rear springs are not listed on their site: http://www.springsnthings.com/
