Please, help me build new engines.
 

I have a 1973 33' Cary twin inboard. I now have 1987 454 MIE 340 HP but the 2-bolt blocks are trash.

I'm thinking about this:
GM block casting number 10237297 (L29 on Mortec)
GM Cylinder Head 12560241 (Vortec 7400 100CC on Mortec)
Scat Crank Part Number 9-10454L (cast)
Connecting Rod Number 3-10212764 (cast)

I plan on using the existing front accessories and brackets.
I will also use the fairly new rear mount freshwater cooling.
I don't know about the flywheel or bellhousing.
The Thunderbolt IV is new and I plan on using it.
The current carb is listed by MC as for a "454 MAG"
The standard exhaust is fairly new.

I plan on getting some type of HiPo intake.

I would like to make as close to 400HP at the prop as possible.
Also, one of these will be counter-rotating so that I don't have to spend anpther 12,000 for trans and engine bed re-rig.

So, what piston? ( I want to run 87 Octane) What cam?
Also, will a 502 Mag MPI VST or Cool Fuel like the ones on Ebay fit on this?

Thanks for your thoughts.

IMO, the parts you have listed are nothing special. Why not just buy some good crate engines, take outs, or long blocks?????

Making 400hp at the prop is pretty easy. Your biggest obstacle will be finding a counter rotating engine.

This setup is on Ebay for $1300.

http://cgi.ebay.com/ebaymotors/New-4...QQcmdZViewItem

That souns a lot better than a crate for 5000.

Ok, I'll do it myself.