The biggest gain you will find is by putting a 1.600 dia exhaust valve and a 1.88 dia intake valve, All the flow goes down the TOP of the ports, both in and ex. do not waste any time on the floors, What I have done for people who want to try this is port one in and one ex port to show them what works, then they try to copy it,If you dont have a flow bench to measure your work, there is NO way to tell what your results will be. A fully ported set of heads on a strong 289 or 302 can be worth as much as 45 HP. A mild port job is worth 20 to 25, IF you dont do anything stupid.


JOE SHERMAN RACING ENGINES