Calibrating A Kossel Delta Radius

Hi,
To pass this spring break I finally got around to building a 3D printer, a project which I've wanted to do for a long time. I bought an Anycubic Linear Plus Kossel and everything went fairly smooth in the assembly until I reached calibrations. I've gotten the towers level with each other, and at the center of the bed the nozzle puts pressure on a sheet of paper when z is at 0 mm. The issue is that at tower positions (-69.28,-40), (69.28,-40) and (0,80) each of which are directly in front of a tower, the nozzle hits the bed above where the printer thinks z is. I've been playing around with my configuration, tweaking "delta_smooth_rod_offset" to try and change delta radius but the closest I've gotten to flat was at a value of 158 (151 was the stock value) where I got the nozzles to hit the bed at 0.4 mm. I'll post the Delta Settings below to see if anyone whose willing to look can spot any red flags. I also think that maybe the lead screws that hit the limit switches on each rail provided in the kit are just too long so I might buy extras and try cutting them down to make shorter lead screws since one of mine is currently bottomed out and can't be tightened any further . Any suggestions would be greatly appreciated. Thanks!
//================================================== =========================
//============================== Delta Settings =============================
//================================================== =========================
// Enable DELTA kinematics and most of the default configuration for Deltas
#define DELTA
#if ENABLED(DELTA)
// Make delta curves from many straight lines (linear interpolation).
// This is a trade-off between visible corners (not enough segments)
// and processor overload (too many expensive sqrt calls).
#define DELTA_SEGMENTS_PER_SECOND 100
// NOTE NB all values for DELTA_* values MUST be floating point, so always have a decimal point in them
// Center-to-center distance of the holes in the diagonal push rods.
#define DELTA_DIAGONAL_ROD 267.5 // mm
// Horizontal offset from middle of printer to smooth rod center.
#define DELTA_SMOOTH_ROD_OFFSET 140 // mm
// Horizontal offset of the universal joints on the end effector.
#define DELTA_EFFECTOR_OFFSET 40 // mm
// Horizontal offset of the universal joints on the carriages.
#define DELTA_CARRIAGE_OFFSET 26 // mm
// Horizontal distance bridged by diagonal push rods when effector is centered.
#define DELTA_RADIUS (DELTA_SMOOTH_ROD_OFFSET-(DELTA_EFFECTOR_OFFSET)-(DELTA_CARRIAGE_OFFSET))
// Print surface diameter/2 minus unreachable space (avoid collisions with vertical towers).
#define DELTA_PRINTABLE_RADIUS 116
// Delta calibration menu
// uncomment to add three points calibration menu option.
// See [minow.blogspot.com]
// If needed, adjust the X, Y, Z calibration coordinates
// in ultralcd.cpp@lcd_delta_calibrate_menu()
//#define DELTA_CALIBRATION_MENU