235 motors are susceptible to all the same kinds of performance enhancing work that other motors are, within the limits of the design. Can you put big giant cams in them? Sure you can, I have, but they react just like any other motor with a big giant cam, the power band goes higher, idle quality goes out the door, all kinds of stuff. Will they make the motor breath like a wind tunnel, nope, the design restricts the breathing and there is no real work around for that. Can you go too far, yep, I have and learned my lesson. That being said, there are more then enough enhancements you can make to a 235, big and little, to suit your needs from a stock motor to wild (relatively speaking, lol).
Mild performance cams in the range of 264 degrees with lifts in the .450 to .480 range have been sold for years by most of the old line cam companies. Very good idle, improvement in breathing, better performance. I would have to dig out my vintage Clifford catalogues but I am nearly certain that Jack Clifford sold his 264 hydraulic cams as a nice entry level cam for an essentially stock motor (he may have even referred to it as an RV cam). Cams in the 270 degree to 280 degree are more testy for a street car with rougher idle and increased power bands (read higher rpms to start making power). At the moment, one of the motors I have is pretty modified and I like a rough idle so I run a cam that is 280 degrees and 492 lift on the street. Ran that motor all over Bowling Green Kentucky a couple of weeks ago, ran perfect, sounded great, no over heating, idles just fine. Did it idle like a stock motor, well, no it did not, lol, but its what I want for right now. Some day I may very well tire of all that and go back to a stock motor.
As for using the 261 truck cam, sometimes referred to as the corvette cam, I have never thought that that cam was a very good performer. The specifications are only slightly more performance oriented then a stock cam, and I mean only slightly. But some really like them and swear by them. Good idle, little tiny performance improvement, but I think there are better grinds on the market that will run way better then that cam and idle just as well. If you are not sure, call the cam manufacturer and see what they advise. I like Schneider cams because they treat me well every time I need a good cam, but there are other companies out there as well.
Dual carbs and triple carbs, I have run triples, they can be a big pain to get them to run right, especially on the street. Not impossible but they can be a challenge. When I have run them, I usually went with the small 216 version of the Carter YF carb. Nice simple carb but still very difficult to get them to idle well or run clean. I prefer dual carbs, and I have had very good luck with them over the years. For a stock 235, or a slightly modified motor, I have had the best luck using a pair of Holley Weber 5200 1974 Ford Pinto carbs. Nice progressive two bbls with small primaries and progressive secondary's. They sometimes require a little tinkering here and there, and you have to sort out a little linkage, but in general, you can bolt them on and they will run pretty good right out of the box.
On the other side of the coin, if you don't want to tinker a bit, and you want the most reliability you can get, then modifying a motor is probably not what you want to do and so a well built stock style motor will be the right ticket. There are no real absolutes here so there are no right or wrong rules, lots of alternatives, except replacing you 6 motor with a V8, which is blasphemy, lol.
