txboater

Can anyone explain what the difference is between a regular ALPHA drive and a "454 Magnum" drive?

I see it listed on the parts page for mercruiser and on my outdrive as well, but cannot find any data as to why the different call out.

Thanks y'all!

panteraman28

None, the difference is with the engines . a 454 mag with the alpha is detuned uses a 330 intake manifold

txboater

Thanks Pantera,

I thought it was motor related, however when I went to get the exhaust bellows, it has 2 part numbers, 1 for the 454 and one for the regular Alpha. Of course the 454 was more $$$

Thanks

puder

i had the 454mag alpha setup

the difference in the drive is the gearing it has 1.32:1 gears as oppsed to 1.48:1 or 1.50:1 gears. Also i heard most of these setups used an engine mounted raw water pump. And had coolign isues. Mine always ran a little warm.

As for the engine it is NOT a 454 MAG that has been detuned. At least its not what we think of when we hear MAG. It has all cast internals and most likely 2 bolt mains. And is (as far as i can tell) a bone stock 330hp 7.4. Mine had large oval ports in the heads. All cast internals and 2 bolt mains. Nothing special about it.

Whereas now when we say MAG it means it has the better internals including the forged crank rectangle heads and heavy duty connecting rods and the rest of the heavy duty goodies.

txboater

Hey Puder,

I think you are right about the water intake. I intend to put on a drive shower this year. The water intake looks like it runs right from the pickup to a little 90 degree hose and then through the transom assy.

This is blocked off right now.

The Magnum I think is different than "Mag" as well. I am putting in a 502 Mag in place of the 454. 4 Bolt mains. The 454 was 2 bolt.

Those gears will need to go, I think, maybe put in a set of 1.5:1

OSO is great!

txboater

Boy I "think" a lot tonight!!!!

cuda

I replace an 888 drive with an alpha that said 454 magnum earlier this year, with a hi perf 350 engine. My wrench didn't say the drive was any different in ratio than any other alpha, and I am pretty sure he would have told me so. With the slip numbers I was getting with the last prop, I sure hope it isn't 1:32!

puder

i know merc used the 1.32 gears because they were stronger than the other ratios. With a 454 and teh 1.32 its was right on eth edge of breaking at just abotu anymoment with the less reliable gears you are just inviting breakage.

Katdrvr

txboater,

Be carefull with that 502 using the Alpha drive. Even with the "stronger" 1.32 gears, that 502 will put out a lot more power than the old 454 Alpha combo ever did. The outdrive will be a time bomb waiting to go off.

mike

puder

dude are you breathin the pipe? Crack isn;t a good thing you know....

a 502 and a 1.32 alpha just isn't gonna work. a 330hp 454 and an alpha is on the edge. Pull the drive and transom assemblie and sell it and find yourself a bravo setup. The conversion is easy. You drill 2 extra holes and bolt it on. The pumps, block off plate and sterring shoudl all fit.

DO you want to spend some coin now maybe a $1000 extra or 4 weeks from now in the middle of the season. That way when all your buddies are out havign fun on eth water you are sitting in your engine bay sweating your balls off fixxing your boat?