I have a '63 VW pan. My 2276 doesn't seem to overwhelm the chassis. I will follow up in six more months however
I do think a smaller motor would be more in the spirit of what these cars were designed to run with the available technology back in the day.
Yes, a smaller engine is more in keeping with the original cars, but who wants that? A 1600 cc won't keep you up with modern traffic, and it's a waste of money. Your 2276 is just right. Good choice.