big or little u-joint?

ok, maybe a stupid question....
I am swapping from a 360/904 to a 440/727 in my 69 Barracuda. the 440 is nothing crazy and I don't at this point plan on building anything real crazy to put in it.
My old driveshaft has the larger u-joint in the rear and then tapers down and has a small u-joint in the front.
727 is about 4" longer than 904 so, I need to shorten the driveshaft.... 4" is right about where the taper is so, should I go with a larger u-joint up front (have to buy a new weld-in piece for the driveshaft) or stick with the smaller u-joint up front and just have the rear cut and shortened?

I guess the real question is, is there much of a difference in strength between the large and small u-joints?