a friend of mine told me that you can put on some 361 industrial heads on a 390 block. and all you would have to do is drill out the water jackets a little so they can line up. i just wanna know if this is true? what kind of power/torqu i can expect? if 391 heads would have the same idea? where i can find a pair and for how much?

also, if this is posible, are there any other mods i would HAVE to do to make it work?

and if you would like, tell me about any other mods i SHOULD do :-)

 

Why would you even concider doing this? You will loose power, not gain it because there will be a drop in compression and the ports and valves are smaller than the 360/390 head.

 

You should stop listening to your friend
Sure, you could put 361 heads on a 390 if you wanted to bad enough, but why would you want to? 361-391 are medium truck engines, low rpm torquers. The heads could be bolted to a 390 block, but the heavy valves, springs, everything are set up for low-RPM use, exhaust manifolds are different, just a whole lot of work to got through make your 390 produce less power and go slower. The kind of power it would make would be measured in dogpower, not horsepower. If your friend was implying that the swap would be for the good, again, PLEASE stop listening to your friend
If you do have a '72 F250 with a 390, you probably have the D2 heads, which are one of the better heads to start a build with, many use them on hotrod car engines
If you want any good advice, other than stop listening to your friend, let us know what you want to do with the truck, towing, mileage, what? Condition of the engine now, and why you want to, or think you need to, tear into it? Check some casting #'s of the intake (2V or 4V?), heads (between the two center plugs- and get ALL the numbers), etc. Type of exhaust on it? Auto or manual?