Oddball stroker question

Ill sell you an intake for 25$ plus shipping, but it has a lot of corrosion in the water passage up front, and may need some repair.

As to the compression and cam choices are pretty limited, It has to run under heavy load for extended periods on crap gas, and a bigger cam is a no go due to water reversion with a narrower CL or more duration. I can spin the motors up to 5500 MAX but will prop it so they max out at 5000 or so. 383 Chevy motors make 450 HP withing the same constraints, so I figure a 408 with decent heads should be the same, especially since a stock 360 Magnum can make 300 with a M1 dual plane and a stock cam. I cant imagine I couldn't make another 100 to 150 with a bigger cam, a blueprinted true 9 to 1 compression, a better intake, and better flowing heads.