That data is missing some info. On non-letter series 300's, at least in 64 it was stamped V41 HP, 63 was T41 HP. My 64 300 sport series had a funky 413, originally stamped T41 HP with the T overstamped by a V. Heads had the 63 head castings with the 64 valve covers, that was the 4 bolt/6 bolt transition point. All of that was mildly interesting to me but I really wasn;t a numbers guy, first thing I did was put a set of worked 906 castings on it.

We won't even get into the max wedge 413's of that era as we are getting away from the OP's setup. Other than to say if it was stamped T41 MP you;d have a low compression max wedge and f it were stamped T41 MP HC you;d have the high compression maxie. Or whatever year letter code applied. But that is after the OP's engine was built so not applicable and to the best of my knowledge was never put in a 300, letter or otherwise.