On my boat the stickers say 1988 Sea Ray SRX 7.4 LITER 330.
I know back in the day 454's started at 315 hp so are these magnums? It's my under that most pachanga ' s had magnums. If so...can anyone tell me the difference in the motor's?? Any info is appreciated greatly

No they are standard 454 with cast internals. Mag motors have forged internals and better flowing heads.

So are the mag's all 365 ' s then? And could it really be as simple and throwing some new pistons in and magnum heads on mine to get the power?

I could be wrong, but for some reason I was thinking the Mags are 385 hp.

Buck

Oh see I dont know. Realistically there's not such thing as to much. But there's also no reason to repower a boat with less than 300 hour's on her right

Carbed mags were 365. MPI mags were 385 if I'm not mistaken.

Too change yours to mags you would be pretty much changing everything except the block.

Actually, he would be changing the block too. The mags are 4 bolt blocks.

Well shiot that's not worth it on this boat at this point in time I was searching through the numerous posts about ways to get more hp out of the 330s and it sounds like pistons ported head better intake.

They seem to max around 4450Rpm which I'm told is the right rpm factory for these motors turning 21 pitch cleaver props I can break 60 but I was also wondering...If I ran 23 pitch props...what we'd my rpm drop to probably 4000 or less huh