I guess we all know that there are a bunch of port types out there that can be performed on an engine, some are safe, others leave the engine with very short life expectancy.

What i want to know is, what is the most agressive port that can be run while still maintaining good reliability? I did a search, but as you might imagine, it was very hard to sift through all of the topics on porting to find what I am looking for.

 

BTW, assuming a 4 port, non-turbo setup. I know that 6 port options are pretty limited.