If you have good compression and no or minimal oil loss go for it.
You will need to decide if the cost per gallon and availibility are worth it to you.
If you are planning on any up grades I would suggest at least doing the heads.
If this will be a bi-fuel rig I would also recommend a "Dual Curve" by MSD (You can get it through your lp supplier) It will allow you to run two timing curves an advanced one for LP and the std curve for gas

Regards