The casting number is too late for a 273, and I don't believe there were any "cop car" 4-barrel 318 intakes made with 318 ports. If there were they are extremely rare. What you have is a 360 intake even if it came on a 318. It's really heavy, has EGR provisions and is a very good intake for performance, better for example than an Edelbrock Performer. I'm using one like it on my 86 318 because I got it for $15. It's a spreadbore so I may end up using an adapter to use my 600 Holley. Mileage is a factor so a Q-jet or T-quad are also possibilities.

All in all, not a bad intake.

R.