How many of us have asked this same question? If you were looking to go from a 454 mag 365hp to a 454/502 at 425-450hp and you already had a running motor what is the best route? There are GM long block 454's and 502's available in that power range for around 5k. Sell the existing running 454 mag long block for 2k or so, add in 1k for labor to remove/swap accessories/replace and that's a net 4k for the changeout.

Compare that to rebuilding the 454's (either roller lifter or flat):cam, lifters, head work,rockers,studs,gaskets,dyno. I think that wou would definitely have more than 3k - probably 5k into the motor with the same hp as a new long block.

Another thought - sell the 454 mag complete and buy a low hour 496HO take out - say the new motor is 8.5k and you can sell the 454 mag for 3.5k - net 5k and completely new motor.

Any thoughts?

Do the takeout 496 mags include everything ready to drop in boat and run for $8,500-$9,000?????? Like igntion,fuel injection,computer. If so I would do that.

Take out 496mag HO seem to be in the $9000 range complete drop in.

Don't forget to factor in down time. You are writing this post at the beginning of summer and I know you want to be boating and not sitting around waiting for your rebuild. I have put a motor in on Friday night, put on the accessories and had it in the water late Sunday on the same weekend. It might take you another weekend or two or three to tune it but at least you are on the water.

Hey Powerguy,
If you don't mind a red engine vs. black, I know a place to buy 496 Volvo Penta test engines. Shawn sells the 375HP complete for $5500 and the 425HP for $6500. You need to use your coupler and bell housing, but everything else is there.

jhnrckr- I absolutely agree with you. My plan is to run the present motors this year and swap them out over the winter or possibly run for one more year. I would then have either long blocks for sale with 350 fresh water hours on them or if I were to go the volvo penta route I would have complete 454 mags available to sell.

Pat-
That seems like terrific prices on those volvo engines. How severely are they tested and do they include any kind of warranty?

Dave

No warranty. Don't know what they do.
Bought mine with 37 hours on the ECM, now has over 150.
1/2 the price of new, so I thought it was worth the risk.
Shawn is a stand up guy, he doesn't sell junk.
I think 5 or 6 OSO members have bought from him.
A friend of mine bought a small block for his Donzi, running great...

Didn't Top DJ buy a Volvo test engine also?