IML: 413 Engine Identification

I'm in a quandary about what engine I have. I finally got around to do some heavy duty fixing on my 1964 Crown. I had a bolt broken off by previous owner to replace. Plus a radiator to get re-cored, as the one in the car had numerous repairs. Got the radiator out no problem. then to the broken bolt in the water pump housing. This is the big cast piece that attaches to the block. The bolt that was broken was the long one that attaches the idler pulley. It is 5 inches long. The second bolt was frozen solid too. I decided rather than snap it off I cut the head off. with all the bolts out the housing would still not come off. The two long bolts were rusted to the housing. I used heat penetrating oil. finally the housing came off. I was still unable to remove the remaining pieces of broken bolts. I ended up cutting them flush with the block and VERY carefully, using cobalt drills, drilled them out one drill size larger each time till the side walls were so thin I was able to re-tap the holes to clean out the threads. No need for helli coils. I was lucky I was able to center punch the started hole darn near perfect center. Well, now that I was this far why not go ahead change the timing chain, gears, and front seal. too. That's when I figures why not clean the crud off the block too. I covered all the essential stuff with plastic & used my home brew engine degreaser, followed up by the power washer. Wow a clean engine! I could read the stamp on the block. It reads:

I tried to look up that info in my FSM, Chilton books, and of course the IML resources. Well, my eyesight must be getting bad but with age, or to many late hours in the shop. I found no V 41. Does anyone know what that stands for? It seems so far if I order parts for a 1964 413 I get stuff that fits. Any help would be appreciated.