1965 Barracuda 273 rebuild...intake code?

Jim Lusk said
Mid-late 1970s intake there. Ports are much bigger than the 273 ports. The intake will work, but it's not ideal.

I'm curious as to why they would install a late model intake...it did run very well but had a low end rattle so that's why I'm taking it apart. Also has hydraulic lifters ...not original solid lifters.
Thank you for your response!