I have run them both but always in dual carb form. The 32/36 Weber is a progressive two bbl with a small primary and a larger secondary. The Holly/Weber 5200 is nearly identical and was actually the 32/36 design licensed to Holly for the Ford Pinto and for the Chevy Vega and others, all small four cylinders. So I have always thought they were too small to run as a single carb on a 235. They run great I agree but it does not surprise me it runs out of steam at some point.
The 38/38 is not progressive. It dumps both bbls at the same time which is probably not what you need with a stock motor. Those 38s are really a higher performance carb then what you need or should want and aI don't know that the bigger is better option is going to work out all that well.
The problem is, as you may have discovered, is that the Rochesters can be problematic as 60 plus year old carbs. Between being rebuilt by who knows how many people in the past, with who knows what level of skill or attention, and the warping, and throttle shaft wear and the power piston sticking issue for example. Couple that with the fact that there are just not that many people left that can really rebuild/remanufacture one correctly. I am absolutely not one of those people so I am in the same boat as you when I am building a stock motor.
A carter YF, which could be purchased as a replacement back in the day is an excellent alternative but finding a correct version is getting harder to do these days and you still have to find someone when can do a really good job of redoing one. Those carbs also have some similar problems, but not nearly as many as the Rochesters have.
I for one would love to find a replacement option that is available, reasonable and reliable but that seems unlikely. But to answer your question, I dont think the 38/38 is going to be the answer to your issue.
