230 v 235

[rbuckin111]

I am rather new to this whole thing so forgive if I ask a very basic question. I have a 64 GMC with a 230 straight six. I have seen some Chevy's from the same era with 235. Are these engines essentially identical except for 5 cu in? Why did they have two engines so close in cu in available? Were the 230s a product for GMC and the 235s a product for Chevy's? Will a 235 work in my GMC? I need to do a replacement and I have found a reasonably priced 235 in my area.

Thanks for any help you can give!