Hi, I have a 1969 plymouth valiant with inboarded super stock springs and 50/50 race shocks. My tire size is 315/70/15 mickey thompson drag radial, and a rear end gear of 456. My problem I am haveing is when I launch the rear suspension keeps bottoming out on the shocks and unloading the rear suspension. I gone to the longest traveling shock I can get under it. Any advice would be appreciative. I would like to keep the leaf springs if I could because this is my street car and is driven very often. My 1/4 mile e.t is consistently 11.20's at 5500 ft. elevation. Motor is 9.2to1 m1 single plane and port and pollished 2.02 915 heads. Cam is purple shaft 484. Car weighs 3032 with me in it and full of fuel. Car is full street trim all the time. Front suspension is stock with 90/10 race shocks.  

make sure your using 28 inch fully extended shocks from M.P or another source.24 is minimum but the ones I got long ago had 28 inch extension length.that dont work try using a coil over shock ,lil more money but will work well.thats dam quick combo you have there at 5500 elevation, fess up. heh.  

I also have a 75 shot n.o.s on it,heh. On motor car runs 11.90's. The best pass on the bottle is a 10.91, but it was 1 o'clock int the morning and our air altitude was around 4200ft. I'll try a coil over shock and see what happens, goin raceing this weekend again.  

yeah, if you call jegs they will give you M.P. phone number, their cheap and im pretty dang sure they were 28 inches long fully extended, you wont find this length from any other rear shock,except maybe a truck shock.haha thats crankin at 5500  

if that dont work out find adjustable shock from jegs that have minimum 25 inches fully extended.use a M.P. adjustable pinion snubber and leave 1/2 inch space for an automatic ,if its a 4 speed set the snubber right on the pan, this will control your axles winding up. you may have to chop a lil rubber off the snubber but ya gotta do what ya gotta do, lemme know how it turns out ,got a race against the 10 flat camaro runnin a 468 12.5 comp with canfield heads,Ive seen it run on the street and its a dog, we bet 200 bux on whose faster, his car wont even smoke the tires 200 feet with race radial tires hahahaha I call him the canfield kid but hes around my age,ill buy him an elephant ear with his money and a cold drink after I whoop that cars as. I say he goes 11.0s max. 10k in engine alone, more than I have in my whole dart but I did all the work myself,take care  

340 if this dont work I got a super hooking spring type suspension and guarantee it will plant. it does not use the ss springs though but hooks like a sob and is cheap and well worth the money and reduces driveline shock to boot  

tonites the nite the canfield kid goes down and loses 200 bux ,heh  

let me know what springs you have for your set-up. I'm very interested. Go and whoop that chevy's ass. Bring in some green for the mopar team. Later,  

let me just say the springs I use are very easy on the rear drivetrain, and yes, a.. was whooped ,the canfield kid fell flat on his face,