OK so with the 144 inline 6 pulled out of the 1962 Ranchero I'm ready for the next step. I had thought the next step would be to put it directly into the 1961 Ranchero as is, but now I'm wondering if I should rebuild first, so that I never have to pull this engine again. "As is" is OK but not perfect; not even par. In my test drives of the 62 Ranchero before pulling the engine, the idle sounds mostly good with very intermittent missing. After it warms up, I can bring the idle down and put the choke most of the way open, and it still sounds mostly good. The problem comes after it is warm, and under load. When I am in first or second gear, it swings back and forth between surge and power loss rather suddenly, and repeatedly, with a dramatic increase in the misfiring compared to no load. When this happens, pulling the choke back out halfway calms it down and gives more consistent power, but still with some evident misfires happening. I'm no expert, but to me this seems probably a matter of tuning/adjustment and not likely indicative of serious engine trouble. Is that a reasonable opinion? I'd like to know what the experienced mechanics think. What I'd also like to hear opinions on, is if I were to install now without rebuild, what would be the first things I would suspect (or try to rule out) for these loss of power symptoms? As more background, I did test spark while it was running to see if the misfires were really intermittent like they sounded. I would pull a plug wire, one at a time, to interrupt the electrical flow, and in all 6 cases there was immediate audible loss of RPM. In sum, all of the cylinders are firing some of the time, some of the cylinders might be firing all of the time, and sometimes it sound like all the cylinders are indeed firing all of the time, but only for a short time until some or all of them are misfiring, but only some of the time. (I'm practicing my writing for an Abbott & Costello cover band.) From my handful of test drives, I speculate that the engine is not highway worthy until the power loss fixed, however I don't really know for sure because my test speeds were necessarily limited due to lack of certain amenities missing in the donor car (like brakes... I didn't dare take it to the highway without brakes.) Therefore I don't know how the engine would feel in 3rd gear, in current condition, and continuing the diagnostics was one of the reasons I had thought to transfer the engine to the better-equipped 61 Ranchero. In addition to the functioning brakes, the 61 has another feature popular for highway travel: a windshield! And I won't lie, the ability to sit on a seat bolted to the floor for my next test-drive, after getting used to sitting on a plastic 5 gallon gas can turned sideways in the 62 Ranchero, well... let's just say I've gotten greedy for the luxury of a 60 year old bench seat. Other things I've done (in case you didn't read my first thread) include: 1) cooling system: removed radiator, water pump, thermostat flushed engine, radiator, heater core and hoses until water flowed clean (everything flowed quickly and freely with no evidence of impairments or blockage) reinstalled radiator, replaced water pump and thermostat with new ones 2) charging system replaced regulator from the 62 (appears to be original) with the regulator from the 61 (appears to be Montgomery Ward aftermarket) this increased the upper limit of charging from 13.5 volts to 14.5 3) oil flow blockage no fresh oil was getting to the top of the head removed rear head bolt (driver's side) connected to oil flow channel, cleaned off gunk from bolt and put it back suddenly oil began flowing to the top of the engine and all the way to the front That oil flow blockage couldn't have been done without this forum feedback. I'm not a mechanic but I owned my dad's 61 Ranchero for several years in the 80s and 90s, and received most of my first mechanical lessons from the things I replaced under that one hood. But all that Ranchero experience is over a quarter century old now, and was far from comprehensive even when it was fresh in my head. I'm grateful for any additional knowledge and experience you can throw my way! Especially if you have an opinion on either of the 2 questions I posed early in this post.