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I want to build another motor for my truck and I have 2 choices. 1 a 302 out of a 72 mustang. 2 a 351m I am pretty sure I will get. Either way it is going to get rebuilt. Intake, 4 barrel carb, big cam, new valves, springs, rocker arms, port and polish the heads. Which motor should I go for?
What kind of truck? 4x4 or 2x4? Tranny? What are you going to use it for?
In general, I'd recommend the 302 if you're not going to rebuild the 351M into a 400...
any kind of truck and either alternative is better than the 302. But with the 351m you get a 400 crank for somewhat cheap and then you have 60% more engine than the 302 and if it's a heavy truck you will get similar mileage or better. I just picked up a bronco where the guy said it was a 351m but it was the 400. the valve cover should have a sticker on it that says 351m/400 then the next line it states which it is.
A lot of info available here on 400 builds.
I just picked up a bronco where the guy said it was a 351m but it was the 400
usually it's the other way around. I've been told twice on the Bronco's I've got that it was a 400, when it wasn't.
I'd consider what tranny you have first. A 2wd would be better suited w/ 302 and something like 3.25 gears. A 4x4 or a 2wd used to haul/tow heavy loads would be better suited w/400 and 3.50 or steeper gears. Since yer tearing apart the 351M anyway, making it a 400 would be yer best bet. IMO.
I,ve decided for now to stick with the 302. I have a 1986 2 wheel drive F250. It has the fuel injected motor and I want to build up the other 302 with a carb. I don't like the fuel injection, it has to many problems and I want the carb. I use the truck for daily driving and maybe once every 2 months or so tow a car but it,s mostly a daily driver