429 vs 460

With a choice, build the 460. They are the same engines except for the stroke. The 429 can be upgraded to a 460 by changing the crank and pistons.. Rebuild cost won't be noticeably different. Performancewise, the 429 is a high revver compared to the 460 with less torque. The 460 has much more torque and gets it quicker which is what you need for a truck. You won't notice much difference in fuel consumption. They both need copious quantities - you may as well have the power. Lastly, the 429 was never used in trucks except for the Ranchero. The 460 is just plain easier to find since they were used right up through about the 1997 model year in trucks.