can a pump gas 632 make 1000 hp?the op said his goal is 850-900 n/a.i think 800 would live much longer.

We all know about and we all play the "trade off game" when it comes to building our power. I believe the OP has to decide if he want's to have a big vacuum pump with a soggy bottom end (900-1000) NA motor or something more manageable (800) NA I agree with Mike about longevity, but only the OP can make that decision. I have had both versions over the last 40 years, and lately lean towards strong reliable power over brut solid lifter cam, big cfm carbs that have low engine vacuum, Not talking blowers or fuel injection, but I digress.

the op did not say but im thinking he wants a pump gas engine,something that he can fill up on the way to his favorite boating spot.that kinda limits the hp also.

Agreed!

I agree that a 900hp blower combo is much easier to build, and will be a milder engine. But, 900hp from a 598, or 632 is not unattainable, and the OP clearly stated he doesn't want blowers. So.... If it were me, I'd shoot for 10.5 to 10.75 comp, low lash solid 55mm cam, .904 lifters, 7000rpm, heads that flow close to 450cfm with the smallest chamber you can get, steel shaft rockers, Ti valves, tunnel ram with EFI, and a dry sump for sure. With the money you save on the blower, you can purchase lighter, better quality parts and components to help with longevity and durability. You'd have a hard time making that power with a conventional off the shelf ring pack, and a wet sump. I always think it's cool to do something a bit different. It'd be great if we could get some of the big power NA guys to post their experiences on this thread.

alex,do you think gas ported pistons would be good on this build?i know a lot of drag race guys use them but i dont know about longevity in a marine engine.

A pair of those would sound wicked in a Daytona screaming past the sandbar. I'd buy two tickets for that show :coolcowboy:

or one in a 26 daytona!

oops, I thought for some reason in my head Tinker had a 33 Daytona.

Yes, I'd use a lateral gas port with a lower tension .043 barrel faced top ring. It will actually reduce ring wear because it only applies additional pressure on the power stroke, the rest of the strokes the lighter ring tension will help reduce wear and free up HP.