Hey guys I spun a bearing in my 454. Before I have it rebuilt I have a couple questions. I'm pretty sure the 220 originally came with a small block in it, I purchased it with a big block. Because of the hull design will it be safer if I build a 383 that put out 450-500 hp or a big block around the same HP/TQ? Because of the difference in weight what would I expect the MPH difference to be, and how fast would I expect with these numbers? Will be running a bravo outdrive. Not sure of exhaust yet but it won't be stock. Thanks for the help.

383 and save the weight.

If we're just talking specs, yeah do the 383 all day long. But be prepared, unless you're buying headers (which are $$$$) making 400 hp at prop seems to be a really high end number for a 383 build and it doesn't come cheap.

Im making 480hp with emi manifolds and long tube risers... at the prop Im not sure what the hp/tq numbers are... but my 383 is getting me to 71-73 all day long in my powerplay. Spent about 6k on my motor.

just my .02

I like small blocks. I've got a stroker SBC and love it......But since you all ready have a big bock on hand I would suggest using that. The weight savings using a small block do not out weigh (no pun intended) the hp/tq you can achieve with the big block. The big block will create more torque at lower or equivalent rpms compared to the stroker.

Regardless of which avenue you choose have fun and tell us how it goes.

No replacement for displacement !!

fresh water or salt? if fresh water get a set of aluminum heads and rebuild the 454. same weight as all iron small block and lots more power. and more options for exhaust. (including what you already own.)

Stroke the big block, aluminum heads. I have built several and loved them. That will wake the boat up..

Then...there is always the possibility of the LS motors. I am becoming a fan of these after driving a LQ-9 Vortec Escalade for the past few years...big flat torque curve and 6 bolt main bearing caps...big potential here. Now that manifolds are readily available for $1500 a pair the LS becomes a viable replacement for the old Big Blocks.

I love the old Big Blocks but have to say that the LS certainly has caught my attention.

Thank you guys very much for the help. My engine builder quoted me $4500-5000 to rebuild my big block. 40 over, 088 heads, forged Pistons, h beam connecting rods, balanced. Now I need to weigh my options. What mph can I get with this setup and non stock headers?