Thanks "H". those specs look like the 89 specs( port bevel). I was thinking the 90 cylinder was diff. Do ya feel the port belvel in dergrees will enhance the exhaust port flow. To say the 30% will flow bette than 15%. For example when the exhaust port is widened and raised the taper is increased and the flow angle to the out put of the cylinder should be matched to the increase in witdth and height of port.This may increase cylinder stuffing and enhance the combustion charge as well as pull a higher( larger voulme) intake charge to the bottom end. If so and the same is applied to the transfer ports would the diifferent temp of the charges( intake verses exhaust have an effect on bevel angle. Appling that therory may help explain why my new DCP motor (( Internal Combustion Engine ? )) ((Internal Combustion Engine?)) has an increase top end pull yet suffer a little in the mid. Thanks