My 2008 Toyota 4Runner V6, 4WD have actual blown head gasket, lucky I caught it before gotten worse. I am wondering is it possible to use head gasket sealant instead doing heavy work to replace the gasket.. Blue devil or steel seal which one is better? Fetch me your opinions please.

I love, I mean it I really love my 4runner, its champ. I am still financialing on my 4runner $8,500 left, my first auto loan if I decide to trade in and it will affect my long term credit which is I don't want..

No. Do not do it. That sealant worked as a semi-permanent solution for very old head gasket designs (think: all cast iron engines from the 70's). It is only a very temporary solution for your vehicle and likely will not work at all. You risk total destruction of your cooling system (small passageways in your heater core, radiator, seals in your water pump, etc) if you try this stuff. It's snake oil.

The V6 head gasket job isn't that bad. Find an independent mechanic you trust and get a quote. Do not let it sit for more than a couple days - If any coolant is leaking back into the cylinder on cooldown (assuming combustion ring in chamber is compromised) you will be causing rust in the affected cylinder, and worse yet, could hydrolock the engine if enough leaked in. Do not drive it with the leak, if any coolant is making it back in to your cylinder while driving (lots of white smoke is evidence of this) the coolant will condense on the cylinder walls and get between the piston and cylinder wall, increasing friction as it displaces/mixes with lube oil. Enough of this will cause galling on your piston skirts and not long after that, broken connecting rod coming through the side of your engine. Head gasket problems need to be addressed quickly. Do it right, do it once.