1BAD68"S"

okay so its time to make the heads breath a lil bit better. they are stock and i will be looking to go with the max lift cam for my small block,it is a 30 over motor that just recieved a "freshining" as the motor was already rebuilt 15 years ago but the idiot forgot intake manifold gaskets and took a little water in a few of the cylinders during break in but suffered no mechanical damage. i decided to do a simple bottle brush job and fresh rings and bearings and new arp hardware but i want to keep the iron heads(yes im an idiot)and make the most of them until i decide its time for the aluminum heads. what would be a safe limit for the valve sizes keep in mind i dont know much about the olds heads but i know they suffer from very low flow numbers...this would be a different story if it was a chevy...those are easy

1BAD68"S"

wow...i would think someone would have fielded this one...i would really hate to turn my machine guy loose on the heads and say go nuts but he really wants valve sizes so he can match a cam and intake so i can finally get this thing done and not have any problems because im looking for the most out of this motor and dont want it to fall on its face halfway down the track because the heads arnt flowing like they should....i know there are shops and builders i can talk to but i wanna know what has worked for someone in their daily driven track car cause i know one or more of you guys have these heads and have work done to em....help me get this thing out of my driveway and out at the track so i can start wailing on some mustangs...

olds 307 and 403

Is an olds 350? SBO heads flow close to the same especially the 68-72 olds small block heads compared to early sbc heads. I would get a good modern grind from engle,ultradyne(bullet) and crane. Also make sure you have enough compression to support a big cam, or it will be a slug down low. An adjustable roller tip vavletrain will help also.