Pat McPherson

A Gen V flywheel will not bolt onto a Gen IV carnk...

I had a 330 in my 1989 24' Pantera.
I changed the cam, intake, and added Imco risers to the stock cast exhaust manifolds, but did not touch the bottom end.
The cam was a Comp Cams, but I don't remember specs. I did not changes the valve springs in the peanut port heads so the cam was not that much bigger than stock. Oh, I did also rejet the carb.
Anyway, the engine went from a max of 4500rpm to 4900rpm with a 23p prop.
It ran great for about 120hours then it lost compression in two cylinders. I pulled it apart; two pistons had melted. Cast pistons can not take the heat of a high rpm engine. I would agree with the others that have said the cast pistons are the weakest link.
My suggestion to building up a low output 454 is to use better pistons, cam for 5000rpm max, and junk the peanut port heads.
I think $1500 for a set of Edelbrock large oval or $1300 for a set of large oval Merlins is $$ better spent than for a stroker kit. If the heads you have won't support the added cubes then it's a waist. And if you have to buy both, just buy a new 502 base engine...

z.zuperboat

496 is a good combo. make sure you get the good valves manley severe duty intake and inconell exhaust. go for the better crank and make sure it has not been cut 3 times. adding a fordged crank and an 850 you will be at 5600. $400 more and I know where you can get a 540 / 625hp.

Longrange4u

Well then ZZ help a brother out

z.zuperboat

Longrange send me a PM I will see what I can do.

Big Block Billy

Cast pistons also can have a piece break off of the skirt. It may have something to do with the manufacturing process, with the steel reinforcements in the skirts. I bought two 330 marine motors. When I cranked one over by hand I heard a knocking sound. Turned out to be a broken piston. Talking to a long established marina owner, this is common especially if motor is lugging (overwheeled). The reversion issue is very true, especially if using a big cam. I would suggest a max of .550 lift, 110-112 lobe seperation. Obviously the duration would be limited to keep overlap down, this will limit your cam selection down. I used the 365 mag cam. With head work, Large oval heads, big valves, porting, Better intake and holley squarebore carb., It really ran great in my 24' Formula, Until I lost oil from a cracked valve cover! and damaged the bottom end. ! Also dont waste money on an msd. They stop MSD'ing at 3000 rpm's anyway. They cost a fortune, have steel mechanical advances that break, due to poor spot welds at the factory. We ran the whole setup on a '38 Scarab with 572's. They provided no increase in power. I like the T-bolt IV. Very trouble free. You would be better off spending the money on the inside of the motor, Or on exhaust. My 2 Cents BBB

ECeptor

Helluva plan with one exception - I'd stick with the Thunderbolt ignition if he had one already.

Longrange4u

ECeptor... BBB...Kaama...zz... everyone that has helped me in this board I want to say thank you!!!

ECeptor

Let us know what you end up doing (in detail, of course!) and how it works for ya.

lowflyin

These inconel exhaust valves...how important are they? I had a 502 built at the end of last summer by a reputable machine shop in Baltimore and those valves never came into consideration. It's basically stock except for .25 longer rods and a .550 hydraulic roller.

z.zuperboat

Inconel is not important until you snap a valve off crush it between the head and piston cracking off the piston skirt and cracking the block. Thats Y they make sleeves.