1LESSZ28

Looking to get a set of ported heads in the near future and was wondering what gains could be had by portmatching the runners of the intake to the runners of the head? I have heard gasketmatching is bad for velocity and throttle response and ve and was wondering if there are any downsides to portmatching?

I know the stock ports on the intake are smaller than the stock ports of the lt1 head. Anyone know why? Is it for torque, throttle response etc? I really don't want to loose any lowend by opening up the ports on the intake but I figure with the engine drawing more air and more efficiently this shouldn't happen but that is just a guess.

89TramsAmGTA

When you receive your heads find out what the minimum cross sectional area is in the intake track. Ideally you don't want the intake manifold to be less in CSA than the head and become the choke point.

Regarding port matching. Again ideally you want them to match perfectly. That takes a lot of work and is hard to do. So most just make the intake manifold port slightly smaller than the port opening on the head. Rumor has it that it is better to have the intake manifold port smaller than the head but larger is not good.

Z-RATED94

You mention nothing about a cam to go with the heads. If your future set-up is just heads, I wouldn't worry about the intake. If you are going to cam it also, I would worry more about porting the intake, or rather I should say have someone (experienced) port the intake. And then ask them to port match the intake to the heads, IF they think it's worth it.

trax

Here are my heads versus my intake ports. The intake is now in the machine shop for porting. Should be done next week.

user 647483

Match the manifold ports to the head ports (not the gasket) .
Raise the intake roof behind the injectors
Remove the ski slopes.
Open the TB bores to match a larger TB if you are using it.

The shop who machined the heads is probably a good place to start.