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Help with alpha to bravo swap!

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Old 08-25-2005, 07:01 PM
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Default Help with alpha to bravo swap!

I know this subject doesn't have much interest for you reeealy high performance guys but I'm not getting much info out there, even from merc.

I am contemplating swaping my alpha(MR)/260 to a bravo drive and either keeping the 5.7 or repowering to 7.4.

Does anyone have literature or mounting specifications concerning the motor mount positions of the 5.7 and 7.4.

I've done some preliminary measurements on the outdrives and the BII anti-ventilation plate seems to be 3/8" lower than the alpha. Would that be an area of concern if the bravo is mounted at the alpha mounting position.

Thanks for any help you guys can give me,
Charlie
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Old 08-25-2005, 07:19 PM
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Default Re: Help with alpha to bravo swap!

What kind of boat?

A bravo 2 is much deeper than a alpha. The difference is several inches.

I believe a bravo 1 has the same x-dim as a alpha.

You will need to drill two more mounting holes for the bravo transom assembly as the bravo uses 8 studs instead of the alphas 6.

I believe the motor mounts would be in the same location.
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Old 08-25-2005, 07:42 PM
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Default Re: Help with alpha to bravo swap!

If this is something that you want to do, I do have a Bravo 1 drive for sale.
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Old 08-25-2005, 07:46 PM
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Default Re: Help with alpha to bravo swap!

PS I have made this change in the past and I will be glad to help you with any info that you may need. You may e-mail me or call anytime. 434 738-6922
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Old 08-25-2005, 09:41 PM
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Default Re: Help with alpha to bravo swap!

Thanks for the quick replys,
It's a '78 240 searay.

I replaced the transom and removed all the wood in the cockpit and I've started to replace the stringers and bulkheads.

Cord,
Yeah, the BII skeg hangs over 4" lower than the alpha. The anti-ventilation plate measured about 3/8" lower than the alpha, too and I've heard a lot of complaints of lower speed with too low AV plates but I don't know how low it has to be before it affects performance.

Warren,
I have a bravo inner transom plate and the rear motor mount seems to sit about 1/4" further past the transom than the alpha. Did you have any problem with the position of the motor mount? The engine is a 400 SBC but I was also curious how far off the BB motor mounts are compared to a small block. I've only played with small blocks. If you would rather have me ask you questions by email, just let me know

Thanks again guys,
Charlie
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