i currently have 1993 merc. 7.4 or 454 ci. 425hp motors on trs drives and trannies in my boat. what is the current motor swap for my application? will the new 496 ho bolt right up, will a hp500, 525, or just about any BBC bolt right up or are the bolt prtterns different? anyone know about what a rebiuld on mine should be, the blocks are cracked from ice, help???????????

thanks guys for any help

come on, i know there are some smart people on this site, we can't all be this dumb. help???

What boat?

Jon

Motor Mounts Are Different On The 496s ..You Would Have To Redo The Front Mounts ...The Back Of The Motors Will Accept Your Stuff ..Ask Jeff From JC PERFORMANCE ENGINES About Rebuilds With New Or Used Blocks

Well, the bolt patterns on the bellhousing are the same and the rear mounts should be also. But most of the bolt-ons will not work on the 496. Best thing is to get take out dressed engines and they should basically bolt right in.

You can't rebuild if you have cracked blocks, but you might be able to use your rotating assembly in a new block.

496s will bolt to the bellhousings,But the flywheels are different.The motor mounts are also the same bolt pattern and in the same location.So you can take one out and put one in with no realignment.But that is all that is the same . Nothing off of your mark4's will interchange not even the exhaust manifolds. JOHN

I have 2 blocks if interested..........hell complete engines that need some refreashing I need to move. PM me if interested.
@475hp 454 carb .

this is what i thought but my shop is telling me that the 496, 502, or no other blocks would bolt right up to my trans's. i need a guote for both options for my insurance co. and i think my shop is mistaken or trying to make the most $$$ for themselves without being truthfull, imagine that, in vegas none the less. thanks, any more info would be great.

robert

Front Mounts Are Different

I used these guys for my big boat and their service was great. They have decent prices on their rebuilds and you would not have to worry about changing bolt ons.

http://www.ebasicpower.com/engines/index.htm

OTOH-if you need to repower it's always nice to move up in power 502's should fit in your app.