come to think of it i kind of remember reading on the interweb about a 454 with a set of worked peanut port heads,a rob strob hyd roller cam and a flamethrower ignition making 606 hp at 3700 rpm,the torque was the real story at 766 lbs feet.maybe the op is on to something with the peanut port head.

Mike, I think what we in the US take for granted is the cost of fuel and availability and cost of parts. The OP is from Finland where gas is $8.00/ gallon. If he can make decent power at a lower RPM, he is more efficient. Since BBC parts are so easy for us to find here we are at a uge advantage compared to the rest of the world. I could not find on the interweb anything about a 606/766 hp/tq peanut port BBC but did find a lot of information about 550 hp peanut port bbc.
tips on building a peanut port big block combo | Grumpys Performance Garage

I think super Chebby magazine did a head comparison and barely got 500 out of heavily ported peanut heads. They are nice heads unless you are a full throttle kind of person. They work good in my 34 Hatteras...

Thank you Phughes! You know my situation 100%.

i understand his wanting to use existing parts to save money.i can,t see how he is saving money be porting&flow testing a head that can not achieve his goals.when i tried telling him that it won,t work he is insisting on doing it anyway,it,s not my money and after he realizes the peanut port heads are not the answer he will need to spend more money on a set of 049s or 741s.he will wish he never wasted money on the peanut port heads.you will not find the 606 hp peanut port build because it is not going to happen.to the op,as i said before,buy a set of 049s,give them a valve job and go boating,good luck in whatever you decide to do.

the cam i used was a comp cams k11-445-8 kit it has .510 on intake and exhaust 270/276 and 218/224 duration at 050 lift its a great cam for the peanut portland produces a lot of low end tq.my heads were stock and i believe my engine builder used 2in. headers on the dyno.

Can you post up the dyno sheet? Where did it make peak power and how much ?

mild thunder i gave my dyno sheets to the guy that bought my boat but the motor peaked out at 4700 at 430hp and i believe it was 527 torque at 3200 that was at 32 degrees timing

i found an extra copy of the dyno sheet but don't know how to post it on here the motor made 431hp at 4800 and 527tq at 3600