Inliners International Forums General Discussion Engines Swap 250 for 235

I love messing with the 235 and 261 Chevy motors so I will forgive my Inliner brethren for their unkind disparagement of my beloved early Chevy motors, lol.

The thing is, those of us who love the 235/261 style motors love those motors for a lot of reasons. For some, it's the motor they started out on. Others, they love the quaintness of the old technology and the quirks and specialized tools that go along with building and maintaining these motors. Others out of fondness. I love messing with them for all of the above.

But those motors are not everyone's cup of tea. The platform is old technology and in many various ways much much less efficient in both design and power producing ability. It's design goes back to the 1920s and was "the" motor for a Chevy until 1955 when the 265 v8 was introduced. The engineering and design that went into the v8 motors was in part used to upgrade the base 6 cylinder to the 194-292 series motor. So with the later motor you get more main bearings, better crank design, better Rod design, better rockers, valves, intake and exhaust, oiling, filtering, every aspect of the 194/230/250/292 series of motor was an upgrade.

Tom is being really really generous with a 235 making 200 hp. A 55-62 varies in advertised hp from 123-140. That was gross horse power under optomilized conditions and much better building tolerances for the motor used for the tests. The production reality was less, probably 125-130 gross, less at the wheels. 170 hp out of a modified 235 would be considered pretty good but takes a lot of tinkering to get there, (not to mention rpm and gears). If you have never messed with a 235, there is definitely a learning curve to be mastered.

Motor mounts are different, no parts interchange, with the possible exception of the exhaust valves and thermostat, lol.

My recommendation, Stick with what you know and what you have. In the end you will be way happier with the 250 then the 235. If you have concerns with the integral head, get yourself a spare non integral head, install Tom's lump kit, and rebuild the head. Take a pass on the 235. The 250 is a better pick for your situation.