Calvert Mono Split Leaf Springs

Wonder if anyone can help me. I have Mancini XHD springs and have serious spring wrap issues. I solved the problem about 85% by putting 4 clamps on front of spring and raising the pinion snubber. Must be a weak main spring. I talked to Calvert today and they suggested their split mono leaf spring that has a 225 lb. spring rate compared to about 110 on the Mancini's. This is a four speed 383 big block 1968 Dart. The spring wrap occurred when pulling out on a hill or releasing the clutch normally. The car would shake horribly. At first I thought it was clutch chatter, but after talking to a long time Mopar racer, he said immediately that I had a weak main. In fact he said they have tossed Mopar Super Stock springs recently because they had weak mains. Brand new as well. I clamped the springs and raised the snubber and the problem is much better, but not right. I just want to make sure these Calverts are good. I plan on running them without Caltracs bars and just the adj. snubber. Has anyone done this with a four speed big block?

Following, as I am wondering the same thing for my 72 Demon 4 speed that will soon have a 440.

the springs and bars would help alot..

I believe the duster on the cover of the latest Mopar Muscle uses caltracs springs and bars. 1000+ horsepower and the car has not been tubbed OR has had the springs relocated. [but it is not a 4 speed] It's running down in the 8.30's zone in the 1/4 mile. IIRC. FWIW. Back in the old days you just went with ladder bars and sliders. You could also run a reinforced plate and adjustable snubber but I think the caltracs would be better.

omahamoparguy said:

I believe the duster on the cover of the latest Mopar Muscle uses caltracs springs and bars. 1000+ horsepower and the car has not been tubbed OR has had the springs relocated. [but it is not a 4 speed] It's running down in the 8.30's zone in the 1/4 mile. IIRC. FWIW. Back in the old days you just went with ladder bars and sliders. You could also run a reinforced plate and adjustable snubber but I think the caltracs would be better.

Click to expand...

what tires is he running on that untubbed duster? :???:

omahamoparguy said:

I believe the duster on the cover of the latest Mopar Muscle uses caltracs springs and bars. 1000+ horsepower and the car has not been tubbed OR has had the springs relocated. [but it is not a 4 speed] It's running down in the 8.30's zone in the 1/4 mile. IIRC. FWIW. Back in the old days you just went with ladder bars and sliders. You could also run a reinforced plate and adjustable snubber but I think the caltracs would be better.

Click to expand...

This is the car/article he is talking about.

http://www.hotrod.com/cars/featured/1509-1100hp-street-legal-1972-plymouth-duster/

The four speed is the biggest problem when deciding springs. Any 4 speed guys, help please.