The kind of power you are looking for will be very hard to handle on a everyday basis. 292's will make lots of power when built right, BUT it will come with a high price tag. First off, get the book from the above post and read it very carefully. You will start to see why it cost so much, trick heads, cams, intakes, carbs..... Plus these race type, high HP engines run at a very high rpm, 7 to 9 thousand! The straight six was built for low rpm torque. You can boost the power band by adding more fuel and better breathing, but each thing you do raises the usable rpm. Before long you will be out of the power curve your truck needs. Most aftermarket camshafts don't start making power till 2500 to 3000 rpm and with a 4000 rpm redline on stock parts, that leaves little room.
It can and has been done, but it can be done a whole lot cheaper with a V-8. Depending on the weight of you truck, it could take up to 400 hp to run in the 11's. 400 is a long way away from stock! Joe