What ya think about a 90 formula (292) with 900hrs ?
The guy seems very maticulous about everything he does ...but I still feel an overhaul is due ....

Yes. At the very least a valve job.

Ditto that, and if it has been run in salt and still is all stock, I'd say you definately need new exhaust and approaching corrosion problems in the engine water jackets (if raw cooled). As far as 900hrs goes, other than the valve train and corrosion, that is nothing for a well maintained BBC.

BT

here's a pic .....the whole baot is equally clean ....and also the boat is in Illinoise ...no salt ....

I would advise draining the outdrive oil to look for water/metal. I would also advise pulling the drives to look at seals, U-joints, gimbal bearings, drive couplers, and engine alignment. My engines are fine, but repaing the couplers/drives made my "good deal" an "average deal".

I agree with the previous posts about the valve train being freshed.