Searched MUD, other Toyota forums, and the Internet (including Summit Racing and EricTheCarGuy) to make sure I have my specific procedure correctly lined out before firing up the rebuilt engine (including new camshaft). I've recently received a few good tips on the forum, and ran across some good information on the 80-Series forum from @69rambler: Proper 3F-E break-in procedures Here's the status of the vehicle's systems: Engine filled with ~8 quarts of conventional break-in oil supplied by the machine shop that rebuilt the engine, new oil filter installed, lower end primed with oil using a drill and homemade attachment made from an old screwdriver blade (this was done about 3 weeks ago), and oil generously dripped over the rocker arm assembly. Refreshed radiator installed and coolant system topped off (still need to burp it during break-in) - tightened several OEM hose clamps to fix small leaks, will check again for leaks during break-in. A/C system converted to R134a with PAG 46 oil added to Toyota retrofit receiver/dryer and compressor, per Toyota's retrofit Technical Service Bulletin, and system pumped down to 21+ in Hg (good for 7,2400-foot elevation). Power steering pump filled with ATF, will top off during break-in. Clutch system filled with brake fluid, system bled, and clutch pedal adjusted. New H55f and transfer case filled with appropriate gear oil. Front and rear axles filled with appropriate gear oil. Front knuckles rebuilt and front wheel bearings replaced and repacked. Brake system installed with new wheel cylinders and brake shoes on the rear axle and remanufactured calipers and new pads on the front axle. Distributor/rotor/cap, coil/igniter, plugs/wires installed. Fuel system reinstalled with new fuel pump, filter, pulsation damper, pressure regulator, and refurbished injectors. Things I know I need to do/should do before starting: Fabricate and install 2-inch spacer for the load sensing proportioning valve (added OME suspension lift), add brake fluid to master cylinder, and bleed brake system. Connect parking brake cables at rear backing plates. Install front and rear driveshafts. Reconnect speedometer cable at transfer case. Add fuel to fuel tank. Questions: The exhaust system is not completed. I plan on having a custom section fabricated from the exhaust manifolds to the single FJ60 catalytic converter, along with the two oxygen sensors upstream from the Y-pipe, one for each bank of three cylinders. So the oxygen sensors are not yet installed. I wanted to have the FJ60 drivable before taking it to the exhaust shop so they could move it around as needed, but it seems like I'd want to have the 3FE broken in before turning the FJ60 over to them. Are the oxygen sensors critical during the break-in period? If so, I can temporarily reinstall the front pipes with oxygen sensors and catalytic converters for break-in - that's what I'm leaning towards. I've read in a couple of places that I could prime the lower end some more by removing the spark plugs and turning over the engine with the starter several times. Is this necessary since I already primed it with a drill? Wouldn't that defeat the intent of the cam break-in, or does it matter? If I need to run the engine at 1,800 to 2,400 rpm initially for ~30 minutes for the cam break-in, wouldn't that be bad if I haven't verified oil delivery to the top end first? Or would the oil I drip over the rocker arm assembly, etc. beforehand keep things lubricated for that long? Or could I run it for a few minutes at those rpms then remove the valve cover to verify oil delivery, followed by the remaining 30 minutes? Just want to make sure I don't mess things up.