I must disagree. More is not always better, especially when port volume and cam specs are concerned. What is the purpose of this engine? Street, daily driver, strip only? What is the compression, cam specs, how far will you rev it? Maybe you can talk to your cam manufacturer and ask them how much port volume you will need and then look for a head based on that. Big intake ports on a street engine will slow the charge velocity and won't make as much low-end torque - and isn't that what you want on the street?
I agree with "the Vandal". Do your homework, and figure out exactly what you want your ride to be like, square ports are really cool when you are talking to the boys, but for the street and if you wish to drive it regularly, i personally would consider the oval ports.After the engine is in your ride is the wrong time to figure out all the details. Pay attention to the cam and its rpm range, tailor all these parts to what you expect the engine to be like. You might even spend a few dollars and do a "virtual builup" on a desktop dyno program.
P.S. Dont fall into the trap that many people do by running what seems to be cool ,and makes the boys all jealous.After all you will be the one who ends up driving it!
P.S.S give it some serious thought!
guess I just had a squirt boat too long, always had to have square port closed chambers and make lots of R's and lots of horsepower....wasn't but one way to go...wide open all the time...but then I didn't have to fool with stop and go traffic in a jet boat. The other guys may be on to something...if you intend to drive a car on the street with any luck at all, you need to do the research.
I'd have to suggest oval port heads. I run world product oval port heads with 10.5:1 compression on a 489 bbc, and can run 89 octane gas. With a very streetable combination in a '71 nova, I run an 11.4 at 114mph. I don't know why I can run 89 octane, but it may be because I run 0 degrees of advance. Total advance is like 28 or 30. On the street I'm untouchable and at the track it runs very consistant.
I run a 427 in a 68 camaro with 11.25 compresion on pump gas.my heads are large oval 106.9cc port&poloished.4speed man.the trick is your cam duration¢erline.I [email protected][email protected] is not always better but i want more power!good luck.
With that size motor I think the Rectangle Ports would perform better as long as the rest of your combination compliments it. Most of it is what are you going to use the motor for and what will you be turning it to. I love the BB 427s and have tried many different combos with the oval and rectangle heads and I've found the ovals work very well up to around 11.5 or so compression but anymore compression than that rectangle ports have always worked better for me. I think the extra compression builds back a lot of bottom end power that is lost going from an oval to a square and in your case the cubic inches should make up for it. I currently run 12.6 to one with the rect. ports and its the best running 427 (Pretty much an L-88)I've ever built and I wind it to about 6800-7000. The ovals made more low end but I picked up way more mid and high end with the rectangle port than I lose on the bottom with the ovals. The ovals also seemed to "peak out" around 6200-6400 with power falling off above that pretty fast. If you went Oval Port with that 496 then I would probably go with the Merlin Oval Ports.