What would the value of a pair of Gen V 454 mag carb long blocks be with 300 hrs of fresh water use, or as a complete motor take out? Weighing the options of rebuild for more power compared to just selling the existing long blocks/complete motors and just installing new long blocks or new complete engines. Complete service records on motors from day 1.
Comparable sales appreciated.

Looking to go from 454 mag 365hp to around 450hp which should add 8mph or so which I can get with a mild upgrade, new long blocks or take out 496HO. I assume that many others here have gone down this same road...........

GenIV 454mag, going through upgrade. Ya know PG.

I've bought them in the past for $2500 for long blocks.at 300 hours you have to figure they need rebuilding.

I would use what you have and just put stroker kits in them. Replace crank rods and pistons, go through the heads with fresh parts. Change the camshaft profile a bit and have a pair of 489's that will make the power you want easily. Probly get them done for $8K total.

Chris

Here is the dilemma, new take out 496ho's are 9000 delivered plus 500 to swap it out for old motor makes it 9500 installed. If I could sell the 454 mag for 3500 complete which makes a difference of 6000 for a new motor installed.

The comparison I am looking at is rebuilding by present motor, buying new exhaust and more labor to remove/strip/install motor. Basic rebuild I am hearing will be 4000 plus 2000 for exhaust and 800 labor is 6800.....more than the net for the new motor....and my rebuild motor still has old bottom end and accessories.......and the new motor would need 450hp at the crank/425hp at the prop to be comparable to the 496HO.

where can you get take out 496 HO's for 9K? is that each?or the pair if you can get them for $4500n each I wouldn't hesitate but 18k....NOT, build your own power.

I wouldn't pay 3500.00 for an old long block. 2000.00-2500.00 maybe. Also, are the 496's complete with f.i. and electronics. I don't know if they will run as well with your accesories. I would build yours with a stroker rotating ass. and get 500 hp for the same money.

Dyno - 496HO's are complete drop in for 9000 delivered.

PatriYacht - I was thinking 3500 for the motor complete drop in.

If the long blocks are worth 2000-2500 and new 502/500 crate marine long block is 6000 or so what sense does a 4000 rebuild on a 454 make?

What kind of warranties to the 496 T/Os come with?
And is merc power what you want?

And why are you repowering? are your blocks tired?

GM crate 454ho's are less than 5K....$4995 I think....Summitracing.com !!!!