questions on BBC heads

[tiger9297]

Which is better oval or rectangular port?

I was looking at the Merlin II BBC cast iron heads, the Dart Iron Eagle BBC heads and the Vortec L29 BBC heads. Is the quality of these heads over stock heads worth it, and if so which of these 3 is best?

 

[ryan22re]

Oval ports for the street and towing, rectangle ports for the track.

 

[yellowK20]

The Vortec would be a good choice

 

[tarussell]

Keep in mind that the Merlins will have a much better deck thickness than the Vortec's - less prone to cracking and warping.

Oval v/s rectangular absolutely depends on where you want the power band to be, along with what mods are made to the motor and weight of the vehicle.

Tom

 

[ol rob]

Oval ports are for low end grunt. Less than 6000rpm. 90% of all engines would do best with these. Get open chamber design if you want to be able to run the cheap pump gas.
Rob

 

[tiger9297]

I'll be using the truck mostly on the street and towing my boat and camper. I definitely do not need high RPM horsepower and definitely DO need low RPM grunt.

Do most of the stock oval port BBC heads flow pretty well? I'm asking b/c I was wondering if it's even worth buying the aftermarket heads. If the stock heads perform well I should just stick w/ them and save that $1400.

 

[ryan22re]

I think the "049" casting number head is the best there is, it that's what you've got. Unless the heads need a bunch of machine work and new parts, I'd skip the aftermarket heads. I would have the heads inspected by a trustworthy machine shop before I made my final decision.

 

[tiger9297]

I think the "049" casting number head is the best there is, it that's what you've got. Unless the heads need a bunch of machine work and new parts, I'd skip the aftermarket heads. I would have the heads inspected by a trustworthy machine shop before I made my final decision.

I went to my friend's shop today and looked over his assortment of cylinder heads. He has some 049's plus various others. We then went to three of his Chevy manuals to compare and according to all three the 049,781, and 236 heads are all identical. We found this on a number of heads. Different casting numbers but the same exact specs. I have no idea why GM did this. Who knows.