GM Powertrain thinks that forged cranks are unnecessary because the 496 motors are internally balanced and thus create less stress on the crank. I personally would much rather have the forged crank, but it's not my decision.

Go to this link for all of the specs on all three 496's. You'll see that they all have cast cranks and pistons.


496:
http://www.gm.com/automotive/gmpower...d_brochure.pdf

496HO:
http://www.gm.com/automotive/gmpower...p_brochure.pdf

496 HP3:
http://www.gm.com/automotive/gmpower...3_brochure.pdf

Unfortunately, the 496HO brochure was not properly updated when the crank change was made. You'll notice on pg. 2 that the crank is said to be "nodular iron" (cast) whereas pg. 4 says it's forged. The brochure for the other two motors clearly say the crank is cast.

Here,s my reserch on this topic. Called mercruiser they said all 496HO,s have forged cranks. Then I went to mercruiser parts.com and broke down the crank assembly. They show a part# change on the crank on mag. and HO plus a large price increase. I also e-mailed parts at merc. asking if 496HO had a forged crank and he said forged. The brochures are confusing and this is just my reserch.

The confusion continues.

Thanks for the info guys,, although there is still some confusion.

I think w/ the extra tourqe the 496 makes over the 502 the extra compression would require that with any modifications the 496 is going to be on the edge of deto. and would most likely require mid-grade or probably super..

IF it's only a cam and ECU then the H.O. Is a rip off..

Chris, I noticed your looking at a 288 sun. I have a 2002 mid-cabin288. I was having same problems deciding on engines I ended up with 496HO. I also considered the 496 mag. and 6.2 then put on whipple charge, this conbination is the lightest and cheapest HP.

Raylar,Are you able to re-program the new 555ecu?

I think you have to go to Whipple to re-program the 555 ECU. I have read that they have exclusive rights at this time.

Fuelish Pleasures you are correct on the reprogram, and i too have seen many confusing statements on the forged crank issue. The last of which was in HotBoat mag where the stern-drive Q&A guy answered a "wanna whipple it" question, and he said the HO had the forged BUT even the mag witht eh steel was stout enough to take up to 5psi pressure and hold up well.

I guess it will be hard to know until a couple of more years go by and tried and true feedback starts to roll in from the users...

For me it would be as recommended above, work the dealer; get the HO and don't screw with the warranty...