jmz

I have a 454 KC that needs a rebuild. ...2 seized pistons.

It looks like the low h.p. version as the crank and pistons are cast not forged.

It is a'93 model so I guess what a Mark V ?

Anyway here is a breakdown of parts and costs to build this into a stroker 489. I'd love to hear feedback and opinions.


Ignition System, Mallory Marine, SB and BB GM V8, Distributor, Coil, & Ignition Wires MAL9-26000*** $369.95

Scat 4340 forged 489ci crank, H-beam rods, forged pistons, bearings Scat 1-42410BI $2,010.00

Holley 750 CFM Four Barrel Carburetor, Model 4160; Electric Choke; Vacuum Secondary; Universal Performance Marine Calibration 0-9015-1 $429.99

Comp Cams Xtreme Marine™, Cam, Lifters, Springs & Retainers, Timing Chain, XM262H, 1000-5000 K11-232-3 $399.99

Weiand Street Warrior™ Intake Manifold - Oval Port, Square/Spread Bore - satin 8123 $205.99

Comp Cams (V8 396-454) 1.72 Magnum Rockers & High Energy Pushrods RP1411-16 $195.99

Water pump MPR2231M $89.95

Fel Pro Head Gasket Sets Head Set, 454 Gen V 17280 $215.94

Sensors $200.00

Oil Pump Big Block GM V8 High Volume. MELM-77HV* $59.95

Wiring $200.00

Block cleaning and boring $282.50

Fresh water cooling system $1,100.00
Valve job $500.00

Dyno tuning $550.00

Subtotals:

Engine Accessories $2,595.88
Engine $4,214.37

Total $6,810.25

sonicss42

I have a fresh GenV for sale that is similar to what you are planning to build. If interested send me a pm with email and I'll send price, details and pics. I'm sure you'll save at lot of money.

picklenjim

What heads do you plan on using? Stock peanut ports. If so I would forget the stroker part. They won't flow enough air with the extra cubes. Also what exhaust do you plan on running?
As for a carb and manifold I would suggest a Edelbrock RPM Air Gap manifold and a Holley 750 double pump with a manual choke. Then I would disconnect/remove the choke. The cam is pretty small but that will depend on the heads and exhaust you use and if you do go stroker it will deffinately need to be bigger.

mach1magnum

seems like you could do a lot better with a low hour take out get much more bang for the buck

regalman4925

for 6800 i would consider a used hp500. another thing you didnt adress is upgrading your oil cooling system, a must if you are building a stroker motor. the hp500 comes with a good oil system. plus a hp500 is a 502, throw a stroker crank in it later and go to 540 cubes. just a suggestion. i have been trying to find a bare 502 block to do a stroker from scratch. good luck

apollard

A '93 could be a Mark IV or a Gen V.

That's a lot of money, and will only put you in the stock MAG HP range - depending on what heads you have, maybe not even that. I'd look at good low hour takeouts as stated. If you go forward with this, that cam is too small. Call Bob Madera (rmbuilder) for a cam.

Edit: here's a link to a good 330 HP build up for low bucks
http://www.offshoreonly.com/forums/g...e-results.html

pqjack

even a good used 502/415 would be a better starting point...if you want to stay carbed,i've seen some 454 cyclone and hp465 for sale recently

jmz

Thanks dudes.

Good info. This will all be really helpful in making decisions.

I have to find the best way to build this without spending money in the wrong way or having to do it twice...

Everything is on the table right now not comitted to any particular solution. ---like the idea of building it myself just cause but a good take out 502 would be nice but there is a certain amount of unknown that scares me when doing that.

considering buying a 502 short block (new) and going from there but again everything is on the table.

JZ

picklenjim

1990 was the last year of the MK IV. 1991 to 1995 was the Gen V.

pantera232

I built up my 454 with domed pistons, cam, etc.

First thing is watch out for reversion with the bigger cam i have a .6 lift cam. i extended the internal pipes 6" and eliminated that.
I gained about 10 mph but remember you will neeed to try out props as well this is where i gained most of my mph. I used 781 heads but maybe it would be worth running rectangular heads, dealing with old heads is just another nightmare you need to cc them etc and make sure they dont leak or arent cracked.. Good luck happy boating