What are the pro"s and cons of a stock 351m when it comes to power....torque... gas ecomony

 

They don't make a lot of power stock. Torque is decent...economy not great either maybe 8-10mpg.

 

They are just so Bla Bla stock. As mentioned the fuel economy isn't there either.

Good Solid Motor though. only differeence between 351m and the 400 is the rotating assembly, ( crank, rods & pistons).
Last year, John Kasse won his 3rd or 4th engine masters championship with a 351M.

The biggest problem is the heads.

Great motors with 400 cranks and aftermarket heads.

 

Don't beat on 'em too hard, though. Mine's been eating up the pistons since the day I got it. But, it's mainly because I have a hard time keeping my foot out of it with the straight pipes. Economy wise, poor. Best I got was about 12mpg. They're a smog motor, plain and simple.

 

My '79 has a 351m and 3.50 rear gear, C6 auto. If you drive it easily and cruise around 60, I've gotten 17 mpg with the a/c running on a longish trip. Wind it up more (drive faster) and mpg will drop to 12 cruising 70+. It's got pretty good low-end torque, not that far off a 460, but it isn't a high-speed hot-rod engine. For that you would want a 351w.