Of all the Pushrod 60V6s, the Gen 2 is probably the least modified. I offer porting services through WOT-Tech, with most of my experience being the Gen 3 engines. I have done 0 Gen 1, and what I would call a decent amount of Gen 2 flowbench testing. This isn't porting the whole port and flowing it. It is modifying one part of the port, and testing it. Doing something else, testing it. Then the next port, trying only what made gains, and then retrying what lost in a different order. Then many variations of that with more cylinder heads. It was enough to see the differences in what matters between Gen 2 and Gen 3, and I was able to spend more time with the cylinder heads knowing the intake manifolds are big waste of time. I saw no gains from doing anything to the manifolds. I put a rounded clay ring in place of the throttle body. What more do you need to know?
TB. Leave it alone. You aren't doing anything here worth doing. (cost and time vs flow improvement is very poor here)
Upper intake. Leave it alone. You aren't doing anything here worth doing. (design issue, extrude hone the manifolds is your only real option if you must)
Lower Intake. Other than the above mentioned extrude hone route, you can check the lower to head port vs gasket and see how the roof look. Don't match this to the gasket! You need it to be a little lower. Match nothing here.
Cylinder heads. Hell yes we are modifying these.
- Intake port. Gasket match the roof and what I call the far side. The one that goes all the way to the bowl. Leave the other side alone.
- Leave the rocker arm boss alone. You see airflow? Awesome. I see dead people. Stop hallucinating with me and accept reality once again. There is nothing gained here.
- Blend the bowl to the seat on the far side of the intake bowl. That means, not the short side radius. How you modify the SSR is up to you. I have read the books. I have watched the videos. Ill leave em be with just breaking the sharp edges, barely.
- Valve Guide Boss. You can leave this alone, or if you want to narrow it, only narrow it in the straight path to the port. Don't mess with the long way around the guide.
- Exhaust port. D shape that SOB. Blend most of the seat to bowl. Open up the side thats opened up. You can't see airflow. Remember this always. You just left most of the intake port stock after all. Only casting flash can be removed but its the least of my concerns other than in the areas mentioned. You can leave it O shaped, or copy the Gen 3 shape but the Gen 3 shape is better. You can weld in a shelf like the LX9 as well if you want to fill in some dead space. Didn't think it was gonna be like that did you?
Combustion chamber. Copy the LX9, mostly, kinda. I would say, be inspired like a musician or an artist. Some of it matters a lot, some of it you should actually leave alone. GM left those areas alone. Just don't over think it.
Or, have me do a set of heads for you
I might be inclined to do a little before and after on my lumina if there is enough interest. Ill just do the heads, leave everything else the same. Ill install the headers later
TB. Leave it alone. You aren't doing anything here worth doing. (cost and time vs flow improvement is very poor here)
Upper intake. Leave it alone. You aren't doing anything here worth doing. (design issue, extrude hone the manifolds is your only real option if you must)
Lower Intake. Other than the above mentioned extrude hone route, you can check the lower to head port vs gasket and see how the roof look. Don't match this to the gasket! You need it to be a little lower. Match nothing here.
Cylinder heads. Hell yes we are modifying these.
- Intake port. Gasket match the roof and what I call the far side. The one that goes all the way to the bowl. Leave the other side alone.
- Leave the rocker arm boss alone. You see airflow? Awesome. I see dead people. Stop hallucinating with me and accept reality once again. There is nothing gained here.
- Blend the bowl to the seat on the far side of the intake bowl. That means, not the short side radius. How you modify the SSR is up to you. I have read the books. I have watched the videos. Ill leave em be with just breaking the sharp edges, barely.
- Valve Guide Boss. You can leave this alone, or if you want to narrow it, only narrow it in the straight path to the port. Don't mess with the long way around the guide.
- Exhaust port. D shape that SOB. Blend most of the seat to bowl. Open up the side thats opened up. You can't see airflow. Remember this always. You just left most of the intake port stock after all. Only casting flash can be removed but its the least of my concerns other than in the areas mentioned. You can leave it O shaped, or copy the Gen 3 shape but the Gen 3 shape is better. You can weld in a shelf like the LX9 as well if you want to fill in some dead space. Didn't think it was gonna be like that did you?
Combustion chamber. Copy the LX9, mostly, kinda. I would say, be inspired like a musician or an artist. Some of it matters a lot, some of it you should actually leave alone. GM left those areas alone. Just don't over think it.
Or, have me do a set of heads for you
I might be inclined to do a little before and after on my lumina if there is enough interest. Ill just do the heads, leave everything else the same. Ill install the headers later