Waterlife

Hi guys,
I'm a DIYer in Australia
Ive received great help in the past, and hopefully can get some more. Below are my specs as I know them, what's not purchased yet is the EFI system or cam. Please bare with me on specs. And long winded post.
I would like help with CAM selection mainly.
Sea Ray 34 DA about 6 tone. Just after a bit more performance/ torque and keep good reliability.
I'm after best I can do with what I have ( or getting)
Specs
454 gen 6 (2000) HORIZON mag mpi
Block is 20 thou over
Crank is original / forged.
Rods original/ forged but with ARP 7/16 Studs
Pistons SRP JE 212135 domed.23cc press fit.
Crank and rotating ass, all balanced.
HEADS Dart iron eagle 308 cast iron with 119cc chambers ARP head studs to suit
Springs (single) 145lb @ 1.900
Max lift from Dart is .660.
Intake valve 2.250 Ex valve 1.880
Hi flow stainless exhaust system.system.
Compcams Hydraulic roller lifters
Original cam is Roller
Lobe lift Exhaust. 301 Intake .301
Duration Exhaust 227° Intake 211°
Dummy assembly got me .55mm in the hole.
​With all measured parts etc I got 9.58:1 comp
I also have 2 sets of 1.7 ratio compcam ultra pro roller rockers studs ect.
Now just so you know I'm removing all Merc Efi system as it's 20 years plus old. I am looking at Edelbrock pro-flo XT EFI systems upto 550hp.
I want it to idle properly, and I understand that the bulk of you are probably more into high hp. Im just after a cam that will work great say upto but never over 4500 rpm. Original motor was apparently 380hp, Maybe I can get 400- 450hp I'm not sure.
Any help on cam for all this would be awesome.
thanks for any help.

sutphen 30

search articfriends,he tested the edelbrock system,,ecu sucked,manifold was good.I'd source the mani and get either megasquirt pro3 or holley.

Waterlife

Thanks sutphen, but looks like different Edelbrock system to the XT System, Still need advice on Cam though!!!! Any takers???

carnutsx2

I'm going with xm270hr , reasonable idle, litte issue of reversion 270/276. .490"/.503" 112 separation. When I get the project back to baseline I'll switch over to microsquirt with the IAC add on.

carnutsx2

Oops double post

Gimme Fuel

Yes PM Articfriends on here.

Frankly, no manifold on the market will make the big low end torque like the Merc/Ligenfelter big Mag MPI intake will. Everything else you will loose bottom end grunt badly and it will flow enough with couple simple mods for HP level you would be. And year 2000 would have MEFI3 which is decent ECU for what you will be doing, would save a bunch of money to keep it. That searay is a big heavy girl, I wouldn't do anything to compromise low end torque if it can be helped.

sutphen 30

only thing that would make it better,,a whipple system,top mount or side mount will give a nice bump in hp and tq.

Waterlife

Thanks to all, yes i am chatting with Smitty, and he has helped greatly so far....
Hi Gimme Fuel,
Thanks for the reply, i know this is a bit late, but the Mefi 3 maybe ok but i seem to go through ignition modules and wiring is all 20 years old.
Yes you are correct in Manifold / Torque HP department. So im changing to Holley HP ECU and harness. New injectors ect. Keeping Manifold and intake.
Adding O2 sensor to Dry section of exhaust. And looking at cam at present. Seems it was a good idea to ask about the Edelbrock Manifold first as it would have been a costly mistake. 2 motors to do this with. I really just want what most people want, that is safe turn key motors that will run for long periods without **** breaking down.
I know, i know its a boat!! but with the amount of maintenance i do, surely i can have a family boat we can all enjoy for some years to come.
Any more thoughts are muchly appreciated.....