plumb crazy

I have a zz502 502 hp in my 22 Eliminator daytona. Can any body tell me witch is better oval or rectange port heads for top speed. thanks

Kidnova

Loaded question. Do a search on the subject and you'll come accross lots of opinions.

Have fun!!

Griff

That depends on the specific heads you are talking about. If you're talking GM heads, then rect ports.

1BIGJIM

iTrader: (1)

If I am not mistaken, the ZZ502 came with the Edelbrock Oval heads.

Like said above do a search and you will get plenty of opinions.
My question would be, how many RPM's do you want to spin it?

ezstriper

in the rpm range we usually turn max 5500-6000 the large ovals do very well #781's are about the best, more torque and mid....have run them with great sucess in race cars as well....my 482 blower motor I used them as well and worked great...sure you will get many opinions.....buy dyno charts I've seen always give the edge to those heads below 6k....Rob

PatriYacht

If you're talking stock Chevy iron heads, 454 is a toss up between oval and rect. ports. 502 is better off with rect. ports. Mostly this is because of the small intake valves in the oval port heads. If you do some minor porting and change the valves to 2.25 intakes and 1.88 exhaust, the oval port will work well on a 502. But, by that time, your bargain heads are getting close to the price of Edelbrock aluminum or Dart iron heads .........

PatriYacht

For a 502 that turns 6000 rpms I would use Canfield 310 rect. port or Afr 305 rect. port. If you have lots of money, the cnc porting options will make a little more hp.

Pat McPherson

Yes, the ZZ502 has Aluminum Ovals with big valves.

I'd be happy to trade for a set of 120 hour HP500 Rec Ports I have sitting on the self...

ROTAX454

Yes Pat, you are correct. Here is the GMPP sheet on those heads. He really should change the intake along with those rect. heads. Make him a package deal.

http://www.crateenginedepot.com/stor...0-P163C66.aspx

ROTAX454

Plum Crazy, If they look like these, then you do have the 3390 heads, made by Edlebrock for GMPP.