I have a 86 242 LS that has a tired 350 with a type 1 pre alpha in it. Right now the boat goes 42 mph @4800 and I can cruise on plane with 4 people at 32 mph @3200, but I would like a little more top speed AND maybe a lower cruise speed. My option s are to

1. rebuild the existing motor into a 383 or swap in a 406 AND refresh the outdrive.
2. swap in a 2006 300 HP 350 MAG EFI engine and alpha package that hAS 280 hours out of another boat i have
3. swap in a BBC/ Bravo
4. swap in a LSx engine (not sure if a alpha would work with the power it could make)

My budget for all this is about 6000-7000
Give me all your ideas.

I built a 439 BBC for my 242. swapped to a bravo from the alpha and I had a top speed of 68-69 mph.... If your interested, I'm selling the engine that I built for my 242 and putting the stock power back in and selling the boat. My engine has 525 hp and would be perfect for your boat with a bravo drive. I'm looking to get $6000 for the engine. It has 40 hours on it and has great parts in it and was professionaly built... If interested let me know and I'll get you the details.

If you are not going for a super high number ie 65 or so, and efficient cruise and low planning speed is high on the list, you can't beat the BravoIII setup.

I would swap in the 2006 350 MAG setup. You already have it, and you would be saving yourself some big money. You said you were looking for a little more speed, and I'll go out on a limb and guess that if your running 42 mph right now with a tired, old school 350...you'll end up going 8-10 mph faster with the EFI MAG setup. Probably more fuel efficient too. That should put a smile on your face.

Take some of the money you were gonna spend, and buy the wife or kids something nice. What goes around...comes around sir.

In the end, you saved a bunch of cabbage...and everybody including yourself is happy.

smart guy!
100 yrs ago my old man taught me, "if the 1st mate ain't happy, ain't nobody happy!".

When I sold my 32' sedan/flybride cruiser and went to my first 24' Sonic my girlfriend at the time freaked! She was used to having a real head to plug in curling irons and what not.
When I bought the Sonic I bought her her own duffel bag and proclaimed that she could take what ever she wanted as long as it fit in that bag
I made it work by doing all the packing and made her real meals on our portable propane grill.
She loved that boat!

Sorry for the interruption and please proceed

To be honest I wouldn't waste my time with another sbc swap I tired the same thing and the result was about 4mph over the original 260/350. I Then re powered the boat with a 509 bbc and a bravo one setup. The boat now has run a best of 69 mph on gps speedo with a 23p mirage at 5100 or so rpm, motor is making 470 hp and 550 tq.

I also thought about a carbed lsx/ls3 take out, and putting a decent cam in the motor, but the the cost for exhaust manifolds and other parts including the motor was real expensive!! your bell housing and coupler should swap over from your current sbc onto an lsx thats about it. When I went from sbc to bbc everything swapped over ie power steering, alternator, motor mounts. If you plan to keep the alpha with a bbc I would upgrade to a external raw water pump and pick up the alpha will not support it. I ran my bbc with the alpha for a while and had over heating problems with the alpha impeller not producing enough volume of water flow.

Sell it and buy mine with twin 350s....

If not, go with the BBC & Bravo.

agree that that's a huge (and heavy) boat for a single small block.

242's need a lot of power to get moving.... I went through the same thing you are going through when I wanted to modify my 242 SS with a 350 Mag and Alpha. I ended up selling that boat and bought a 242 LS that needed an engine and outdrive. If you want to get over 60 mph your going to need 415 hp. If you have any questions let me know... I've gone through exactly what you are about to do.

If it were my boat.... Always building on a budget, I'd make the 350mag a little more healthy with a bit of cam and head work and possibly some efi upgrades, maybe 1500 all told and run that. ONLY because you already have it and $$'s saved even after upgrades could be substantial. Otherwise.... bbc/bravo