Howdy! Search for assorted phrases and you will find tons of discussion on this topic. You can also post up to the FJ 55 list on the Iron Pig Preservation Society at the bottom of the forums page. My solution to running a stock 350 in my Piggy is a combination of several things. Other folks have had success with other methods. I am using my original 4 core stock radiator. I had the core replaced with a high density unit, at 14 fins per inch. The old one was about 8. I had the lower hose fitting moved from the back of the tank to the bottom, with a 90 degree turn on it. This allows me to run a 19" fan, due to engine/radiator placement. I am using a FlowCooler water pump that puts out 30% extra water. I also am running "truck" pulleys. The water pump pulley is smaller, and the crank pulley is bigger that stock auto style, so it runs about 30% faster. Also spins the alternator about 15% faster. So far I do not need to build a shroud, but I have thought about it. I can go play in the desert at 115 degrees out, and the engine never gets over 180 degrees. Your results may vary!?! John