Well, I'd expect a short lived animal then, because that is absolutely insane to have a male BC that is under a year old at 5 feet long.
Saying that it would not "make sense" based on the size of your snake is misinformation. You would have to look at multiple animals, and subspecies at that age and size to make a conclusion like that. I can tell you that the educated breeders of quality BC's rarely have adult male breeders go beyond the 6 foot mark, and that includes the some of BCC locals.
Few, people understand the way BC's should be fed and raised. If you want to learn about the proper upbringing of a boa constrictor read
THE COMPLETE BOA CONSTRICTOR By Vincent Russo and look for any information in print by Gus Rentfro. He is one of the world's top authorities on BC's.
While there are some large boa constrictors out there, they are not the norm, and the odds of a giant diminish further with a male. Size sexual dimorphism is common in BCs.
I believe that with the PROPER feeding regime, and attention to husbandry there is no reason the O/P should not be able to handle and enjoy a BC.
Most, but not all claims of giant BCs are exaggerated, and when the tape comes out, the length of many snakes is actually far less than what is originally stated.
The boa constrictor is a very rewarding and interesting snake to own and raise.
Go into it with some research and preparation and you should be fine.