JaniH here's two informative threads about what you are planning to do.

https://www.offshoreonly.com/forums/...30s-roids.html

https://www.offshoreonly.com/forums/...l-results.html

Everyone gets their panties in a bunch over the rectangle ports. Ever see the stock mid range torque numbers on a 500efi, or even a 454 Mag MPI? They make more torque than they do horsepower. Lots of it. the big gains when going to a dart, afr, brodix, etc over the gm rectangles, usually doesnt start happening till the higher rpms. At 6000rpm, the aftermarket heads smoke the 088's. At 3000rpm, not all that different.

What made the peanuts work great in a tow engine, was their small valve. Small valve, small port, small cam, minimal low speed intake reversion. Its the size of the valve that dictates the size of the port. You dont put a 2.3 valve in a 230cc port, and you dont put a 2.06 valve in a 345cc port.

if youre looking for big torque numbers off idle and peak at 1800rpm , like in a tow vehicle or rv, the rectangle might not be the best choice. But if youre ok with big torque from 3000-5000rpm, the gm rectangles will get it done. Those peanut heads were designed for a smooth idling 1800rpm peak torque truck engine . I wouldnt waste any money on modifying them, even though the internet will tell tales of some guy claiming he made 600hp and 700ft lbs with some peanuts ..

good information joe but i don,t think the op cares about facts,i believe he has his mind made up.porting the peanut port head is a waste of time&money imo.i hope he posts truthful results on his build.

Thanks for advice! My main concern is exactly the torque from idle to 4000rpm, my old stinger 260 is heavy boat for single small displacement bbc. The coast i am boating at has many small islands and 6mph speed limits between short distances. Everybody knows my stinger aint going to be fast even if it had 500hp engine. It sounds that i was too optimistic setting my hp goals 450-500hp, that was just result of my research from the internet and david wizards book. Have done few small blocks before to my old 225 limited, nothing fancy just milld builds like this. i always start flow testing my heads to see how much they support and build the engine around the flow numbers, because i have learned that todays dyno softwares are very accurate. Dynamotion was in 10hp in my last build and engine before that. Peanut port heads are the worst heads for performance bbc thats for sure, but i just want to find out the grunt/fuell mileage they could make at low rpm and maybe even good amount of hp. What comes to the porting that doesent cost me so much and that is the reason i am smashing my head to the wall 😂

Mike, my junk heads hopefully arrives this week and the project begins. You will see the numbers! Flow numbers first and dyno numbers last 😉

Seaman sounds good! Is your heads worked or stock? What exhaust you used at dyno? Cam duration?

What would be the max cam overlap with gill/ssm style manifolds and silent choice.

You can easily reach your goals if you use a custom ground Bob Straub cam.

I also think custom is the only way to go, not so many tight lobe and short duration cams available.

Find yourself a takeout HP500 roller cam. 222/230 110 LSA .576/.598 lift. A 750 carb. Edelbrock performer intake. That would be my recommendation for this 5100-5200rpm combo with the small heads.