4 port vs 6 port
 

What are the pros and cons of 4 port 13bs vs 6 port 13bs?

Ok first you want to search there have been many posts on this I started one myself. The major difference is that a 4pt can be ported more extensively and is harder to make pass emisions stock. The 6 port has smaller ports 4 of them are open and functioning all the time the other 2 open at full throtte or there about by vacume or can be made to open by mecanical means.

well because i have a 4 port 13 B with a streetport and I just finished rebuilding it and I just want to know how much better it will be( if any) than a 6 port

4 ports are great for all out power,for ported N/A and especially turbos.
6 ports are about getting a nice flat torque curve.Maintaining good idle with small primary ports,but having lots of secondary port duration and volume for topend.In other words,driveability.
Thats where the tuned intake manifolds and aux port actuators come into play.If you know how VTEC works on a Honda,thats exactly what the 84-92 non turbo, 6 port 13Bs are doing with their extra ports.
Its commonly said you shouldnt/cant port them.Its not that you cant,or that it wont help.....They just dont have much material to work with and you dont get the same results as when you port a 12A or 13BT 4 port.
For the record,a TII 13B 4 port is a great starting point for a N/A engine too.They have nearly a streetport from the factory an lots of room for more.Just slap in some N/A rotors and go to town.