Coil over shock spring rates

I was going to modify the suspension on my craftsman turbo cool ( it is similar to a LT1000.)
for more front suspension travel . I saw some coil over shocks on Amazon Canada that were for a go cart .
They come in 6 inch and 8 inch tall versions which would work well and they were cheap. The spring rate was 1200 Lbs on all the ones I saw.
This seems incredibly stiff. I don't think my car's are near that. I can get some 13 inch tall ones that are rated 270 Lbs
locally at Princess Auto but they are too tall.
Would a 1200 Lbs work?

1200 pounds does seem stiff, but if you got the shorter ones with 1200 pound springs, mount the bottom of the shock closer to the frame on the A arm, and you’ll have more leverage effectively lowering the total spring rate if that makes sense.

If you’re looking to build a solid axle, 1200 is probably far too stiff. @AllosKidD21 is the big suspension guru, so hopefully he chimes in

Something to consider is if leverage will be a factory in your setup. A swing arm or A arm is sometimes about 2 feet long. If the coilover is mounted away from the wheel, there is quite a mechanical advantage there that multiplies the force transferred to the coilover when you go over a bump. So taking that into consideration, and if you plan on jumping this, that 1200 lb rating starts to make sense, but I don't know what your design or application is.

Kal's is 330lbs each and that is too stiff. I do have them going straight up and down.