D-150 rear springs for drag racing

I know not an a body, but I think there are more people who would have an idea of how to set up the rear even thought its a truck.

The front coil springs have sagged a bit over the years, it was originally a small block truck, but my grandfather had put a 440 in it. Truck has a 383 in it now and I like how the front end sits, but it has a about 3" to 4" of a rake to it.

I'm not going to be hauling much if anything with the truck, so I could afford to get softer leaf springs if that would help. I'll be racing it a bit for fun, its got a 383 and a 4-speed now. Right now the rear is a peg-leg 8.25 with a 2.94 gear. I have a 9.25 rear with a Sure Grip and 3.55 ratio that I'll be putting in with the leaf spring swap.

I want to order new leaf springs from ESPO springs-n-things. I need to tell them If I just want them de-arched so the truck sits with either 0" to 1" of rake or If I should get springs that have a softer spring rate than the factory 1/2 ton springs. Truck springs aren't like the car springs, the truck springs the front and rear segments are equal.

Anyone know what would be a good setup to help the truck hook up?