KYB GR 2 Shocks for Rear Coil Springs?

[Regular Guy]

Thought about posting this in the suspension section, but it looks really dead over there, and I couldn't find an answer by searching:

I have a '70 C10 and I'd like to go with KYB GR 2's all around. It's not lowered. Front part number I have, 344068, but I can't find a GR 2 for a REAR coil spring, which is what I have--no leafs on the back.

I've just got back into Chevy trucks, got sidetracked by cars for a few years and I'm rusty. Should my truck even have coils? It's been modified with a newer step side box. Don't know if leafs were on it at some point, or not.

Will the KYB 344085 work? It is listed for leaf springs, not coils...

Thanks!