What needs to be done to port an intake manifold? How much of a power difference is there between a ported stock intake and an aftermarket intake?

 

WHat's the stock intake? No matter what I doubt it will be able to flow nearly as well as a decent after-market intake.

 

I have 2 intakes, one of a 82 lg4 305 and one off of a 305 from an 81 chevy van. I dont know what intake you could get more flow out of.

 

Try doing search on this topic. THere should be lots for you to find out. Porting the intake will make a considerable difference to your performance. Rpm's will be able to climb a bit higher too. Aftermarket would be better, but not that much unless you match it all up porperly. Try a search and see what you find.

 

if everything is stock, you will not notice too much of a differnce. You would have to port match your intake to your heads for the best performance gains. Aftermarket intakes are MUCH better, you can get a good one for around $100-$150. I would just go that route than port match.

 

Is either of these manifolds aluminum? If not, it absolutely isn't worth it.

Gasket matching the intake can actually hurt driveability, especially with a healthy cam. What you really want is the manifold ports to be slightly smaller than the head ports. This helps keep the flow moving in the desired direction ("anti-reversion", it's often called). Same goes for the exhaust, but the other way - you want the head ports to be slightly smaller than the manifold/header opening.