X-Head Flow Numbers - What to do

So during Thanksgiving I decided to try and find some free horsepower laying around the garage. I'm building my 340 for the final and last restomod of my 69 Swinger 340. With the cost of the restoration at $20K I can't afford a new set of heads so I have to make my X-heads work. I gasket matched them back in the 80's (yes I'm old) and ran them until this last tear down. I ported the intake and exhaust on one cylinder, opened the push rod pinch point for the intake on another cylinder and then ran numbers on a cylinder as they were before. I'm trying to decide if this is worth all the work. I have good numbers for the ported intake but I am a little dis-appointed in all the exhaust flows. I wanted to get at least 180cfm on the exhaust. I can post pictures next week when I get the head back. What direction do you think I should go? Will exhaust flows in the 145 to 155 range support 240 to 260 intake flows? Camshaft is my old Lunati solid (yes from the 80's). Specs are roughly .507 lift on I & E and 292/ [email protected] duration. Real lift is .487 with a .020 lash. I can post more specs on the motor if you all are interested. If the chart is not legible I'll see about posting a better pic.
Thanks to all who post. I appreciate your input.