Got a line on an engine for the Magnum and need some opinions. I searched and came up with values all over the place.

This engine is rebuilt (0.30" over) and turnkey with all accessories either new or in good shape. The new pistons are KB forged pieces, the crank is a 4-bolt. Engine is a 1990.

Tell me what you think or if someone has a better deal let me know. This is an upgrade over the 350 and I don't want to spend $!$!$! this summer.

I got a Gen IV 454 from a board memeber for 2000 bucks delivered to my doof from Cali. It was basically drop in turn key. I think I replaced two hoses and that was it.

Jon

Buying someone else's "rebuilt" motor is like buying a hooker. You never really know what you got until it's too late. I hope that's your description of the motor and not his.

Here's his description:

454 is a 4th gen. They stopped making 4th gen in 91. 4th gen has the mecahnical fuel pump and adjustable valvetrain.

The 454 was pulled with 200 hrs on it, running fine no smoke, I replaced it with a 550 HP 454 with headers etc..its a toy. I had the 454 completely rebuilt, I was planning on using it in another boat, but I sold that boat and have the engine for it. The crank was perfect, just needed polished, gm steel, 4 bolt mains.

Everything in this 454 was returned to merc spec to run exaclty like it did it 90 from the showroom. The only difference is 30 over Keith black forged pistons, other than the stock Hypeuretic Chevy OE it came with. New cam and lifters, gaskets, bearings, rings etc.

It was built to be dependable and as maintanance free as possible. Comes with all accessories, complete drop in. All the accessories are new (wires...distributor..water pump etc) the only original moving part is the alternator, it works fine. Comes with the aluminum exhaust, pressure tested and magged. Bellhousing....everything.

This just popped up and sounded like a decent deal at $2,500, but I've never bought a used engine. Come to think of it, I've never bought a new one either.

Did 330 hp motors come with steel cranks and 4 bolt blocks? It is going to have the small oval port heads What compression ratio does it have and what RPM's do you want to turn when the boat is done?

ithough 330s came with botyh 2 and 4 bolt blocks. I know i have a 2 bolt 330. But then again my 330 also has large (performance)oval heads.

As for the crank i though 330s used cast cranks. And i know they had cast pistons.

Keith Black pistons are a hypereutectic piston. They are not a forged piston. They are cast with a 16-18% hypereutectic alloy and heat treated. Not as good as forged and better than stock cast. they are only about $300 at Summit.

I bought a 420 with all the accessories for 2k

MkIV 454's came in two flavors in 1990.

330hp cast pistons, cast crank, 3/8 rods, 2 and 4 bolt blocks. Large oval port heads.

365hp forged pistons, steel crank, 7/16 rods, 4 bolt blocks, rect port heads.

This guy's description is not consistent with either motor. I assume his description is not intentionally misleading, but who knows?

mcollinstn hit it. The 330s all had cast cranks and oval heads. Some were 4 bolt some were 2 bolt.