The chart below details our available secondary clutch springs with their forces compared to each other.
On the bottom left of the chart shows 0-vehicle speed.
On the bottom near right of the chart it shows 1:1 clutch ratio.
At the bottom right of the chart is where maximum theoretical vehicle speed is in full shift overdrive (O.D.)
Red/Yellow 218/305 secondary spring reveals low engine speed midrange to top end vehicle speed.
- To increase the engine speed, take the secondary spring final force and raise it.
Next spring to use would be the Orange 215/320 or the Yellow/Orange 225/330
IF having low engine speed (250 rpms low) near peak vehicle speed...
THEN go from xxx/305 to a xxx/320 will raise engine speed approximately 200.  Going from the xxx/305 to a xxx/330 will raise engine speed approximately 300 rpms