My 49 216 has been running pretty strong lately. I've run it up to 65 to pass and it felt like it had alittle more left in it. That said I didn't hold it at 65 for long and normally don't exceed 50. With the stock OEM 4:11.1 rear gear 40 - 45 is it's happy spot.
It starts right up, cold or hot and runs great. I know 216's get maligned by some but mine is proving top be a solid dependable powerplant.

I don't know how much better a fresh 235 is but I'll know soon. Those that have done the swap highly endorse it.

Dave