I'm so late to the game on this that it has already been played and done but,
Apart from the physical appearance of each as compared to the other, what is the big wheeze about Square Port LS heads being superior to the Cathedral versions? Is this some kind of full on race desirability that the one has over the other? And, if so , what is the point if the motor is only going to see street time and never get its mileage added on at the rate of a 1/4 mile per hour?
5.3, my, new to me, LS motor is a 02 which makes it second? generation; they were produced from 2001 to 2006. The heads carry the 706 designator which i.d.'s them as cathedral port and i think I am happier with them simply because the port design seems to place the injector as close to the valve as possible even if slightly higher than the square port does. Apart from that it does use the pull-push cable actuated throttle body, which I think I prefer to the FBW (fly by wire) newer units simply because it is the default operating mechanism in the vehicle for which this motor might be intended.
I gather from all the reference material lying about that one of the big restrictions with respect to this head is the valve size, 1.89" and the fact that it is seen to inhibit the amount of air/fuel that the pistons can suck into the combustion chamber during the intake stroke. Again, this seems to be more about race vs street. Agreed that the valves, at least the intake side of them, could be increased to a 2.02 but there is a cost involved to get there. However, the race on the street is from the last stop light to the next stoplight and it is usually red. Or it is from one coffee klatch to another. This is street racing and it is more about torque than top end as the ride that leaves first usually gets to be the first one ticketed by the cops for "exhibition driving".
So, looking for opinions here. As noted elsewhere, about all this motor would ever get by way of tweaks would be a cam and springs. The cam would fall into the "R-V" category as it would be a near stock lift but possess a longer duration for the pull. I like Isky but Comp seems to offer the widest choice. As for springs, beehives. The closer overall I can stay to stock, the happier my pocket book will be and the happier the motor ought to be.
Nick
Apart from the physical appearance of each as compared to the other, what is the big wheeze about Square Port LS heads being superior to the Cathedral versions? Is this some kind of full on race desirability that the one has over the other? And, if so , what is the point if the motor is only going to see street time and never get its mileage added on at the rate of a 1/4 mile per hour?
5.3, my, new to me, LS motor is a 02 which makes it second? generation; they were produced from 2001 to 2006. The heads carry the 706 designator which i.d.'s them as cathedral port and i think I am happier with them simply because the port design seems to place the injector as close to the valve as possible even if slightly higher than the square port does. Apart from that it does use the pull-push cable actuated throttle body, which I think I prefer to the FBW (fly by wire) newer units simply because it is the default operating mechanism in the vehicle for which this motor might be intended.
I gather from all the reference material lying about that one of the big restrictions with respect to this head is the valve size, 1.89" and the fact that it is seen to inhibit the amount of air/fuel that the pistons can suck into the combustion chamber during the intake stroke. Again, this seems to be more about race vs street. Agreed that the valves, at least the intake side of them, could be increased to a 2.02 but there is a cost involved to get there. However, the race on the street is from the last stop light to the next stoplight and it is usually red. Or it is from one coffee klatch to another. This is street racing and it is more about torque than top end as the ride that leaves first usually gets to be the first one ticketed by the cops for "exhibition driving".
So, looking for opinions here. As noted elsewhere, about all this motor would ever get by way of tweaks would be a cam and springs. The cam would fall into the "R-V" category as it would be a near stock lift but possess a longer duration for the pull. I like Isky but Comp seems to offer the widest choice. As for springs, beehives. The closer overall I can stay to stock, the happier my pocket book will be and the happier the motor ought to be.
Nick
