With L1 Blanket visa, do I need to convert to H1 or apply for a new H1

Hi,

Currently I have L1 Blanket visa and I have completed 2 yrs in US. If I want to have H1, do I need to convert L1 to H1 or should I apply a new H1. I am not sure if both are same.

If both are different cases, then please let me know how long can I stay in US further?

I have heard from my friend that if I convert L1 to H1 then I can stay another 4 yrs with a total of 6 yrs and if I apply for a new H1, then I can stay another 6 yrs.

Please clarify. Thanks!

-Dinesh