650 spreadbore jet size recommendation

[psdperformance]

Hi,
I 'm rebuilding a 650 spreadbore holley. It has 60 primary jets and 62 secondary jets in it. My engine is a 455 olds mild jet boat cam,roller rockers,
edelbrock performer intake,10 qt oil pan. Compression is around 8.1 i think i would have to look in my paper work for compression. I had it setup low compression so i could run 87 octane fuel. I was thinking it is a little lean
as when i pulled the heads off last year the combustion chambers had a brown tint on the valves. I would think it should have some carbon buildup or at least black soot in the combustion chambers? The boat ran for about 15 yrs with the current carb and setup until i last year rebuilt the motor. Any thoughts woulb be appreciated.
Thanks Chris:)

[pw_Tony]

I've always judged a motor running by it's spark plugs. Always went for the brownish grayish. Not black and definetly not white. Some carb shops have "sniffers" they stick in your exhaust for air-fuel mixture. Maybe you can take her to one of those and run it outside their shop with a hose

[DMOORE]

If it ran great for 15 years as it was, I wouldn't change a thing.
Darrell.