Re: replacing 351 with an I-6 300
Got an inline six in my Bronco and it doesn't do bad. It has been modestly built and gets between 12 and 13 MPG. Fuel injection would add another couple of miles. I have a 600 cfm Holley 4 bbl carb on it now. There is 16,000 miles on the engine and the reliability is there. It has torque like a work horse. I have about 350 lb-ft at 1800 RPM. If I had even a smaller carb than the 600, my mileage would be better, but the price goes up for anything other than the 600 cfm carb. Jet a 390 or 465 cfm carb and it would run perfect. My engine can do anything that 351 can do. I did a tug-o-war at a jamboree and did pretty good due to the fact that I could grunt them out, where they had to wind up the small blocks a bit. She ain't no big block, but it can feel like one at times. It will tractor up anything. I have the granny geared 4 speed in my Bronco (NP435) and I can let it idle and I can dump the clutch as fast as I can and the engine won't die. It will jump real good, but it will keep running. I have the carb set up now to where it could almost run upside down. Let me know if you want details on the engine.
If it ain't broke, I can probably still fix it.