Curious if you guys cranked up the timing (on a dyno) until the engine didn't make any more power and left it there or dialed it back a bit because it's in a boat? Mine are set at 33 degrees btdc. Is that in the realm of a pretty standard setting? The thought is to keep it concervative because in a boat you can't hear them knock etc. I am running REC fuel which I believe is 90 octane? Not sure if there is more hp to be had safely or even if that amount of hp (small amount?) would make any difference in a boat. As is they are 500 hp @ 5300 tq is 517 @ 4400. Only 9:1 compression. Thanks for your thoughts.

I should have said that total advance is 33 degrees and it's all in at 3000 rpm.

Lots of guys on here with way more experience than me, but that sounds about right.

might get more replies in teh tech forums not general boating.

Most will probably say 32-34 total.

Had my motor 540 freshened last year. Got it back and had some issues, so during my troubleshooting I checked timing. Was supposed to be 34* but the mechanical advance wasn’t working correctly and it was running up to 44* all in around 3000 - not good. At any rate, boat ran the same mph at 34 as it did at 44. At that low of comp probably wouldn’t hurt anything to try 34 and see if it runs and better.

Moved and merged with his other thread

32-36* is the norm for most BBC builds.

On your typical modded big block with 9ish:1 compression. 34 for pump gas, 36 for race gas. There are a MILLION other factors, but with the info you've given here its a safe bet.

Thanks everyone for your input. I'll leave it at 33 .