Ported t/a - aar heads HP? For an old 340 sprint car

[440dart123]

Not building one just curious on what kind of HP people have gotten out of some ported U heads on a 340 or 360. A friend of mine has an old sprint car that ran a 340 from the mid 70s the 340 looks mostly stock other then it has a big cam alky hilborns and ported 6pack heads iam guessing it would be roughly 450HP at the crank. I will get some pictures as some of you guys would love to see this thing its a time capsule

 

[273]

Stock 400+hp
Home ported 450+hp
Pro porting 500+hp
Extreme porting ( brazing, exhaust valve moved to fit 2.19/1.60) 600+hp

 

[440dart123]

Stock 400+hp
Home ported 450+hp
Pro porting 500+hp
Extreme porting ( brazing, exhaust valve moved to fit 2.19/1.60) 600+hp

Have any links with someone who used these heads, it would be cool to see a dyno run of an old gurney race car you would think that them cars would have been built to the ragged edge