Convert 496Mag to 496Ho
 

What would it take to convert a 496 (375hp) to a 496 (425) other than the Cam and ECM?

What do you thing it would cost and do you thing it would be worth the 50HP?

How much top end is 50hp worth?

Depending on serial number, you would also want to change the crank, but is not imperitive. The older models were cast and forged, for the base model and HO, respectively. Nowadays, they are all cast, so it's not something you need to worry about too much unless you plan more upgrades later. Other than that, you are correct with cam and ECU change.

50 hp might get you 3 to 4 mph, 5 tops.

I heard they only run about 3-5 mph faster than the 375hp...The upgrade new is about 6 grand I think, so you would think there is more to it than the cam and ECM????

bcolmsted - good point!
I priced the two parts. Cam $500, ECM $1400 as priced for both the 375Hp and 425Hp. What I did find out is what Baja Daze stated, depending on the serial number of the HO the crank shaft is either $5,608.89 or $1,203.44.

If it is true that the newer verisions are coming with the same crank than what are we paying 5K plus for?

bcoffield

I have a 375 hp and very happy with it...Most insurance rates go up considerably above 375 hp...As far as the cranks all the same now, I only have heard what bajadaze stated..
I`m not touching mine till warranty is up..

If this is true that both the 375hp and 425 hp have the same crank than why the 5K difference in price. Is it just the fact that we will pay more for the extra ponies?

That's a $100 per pony...anybody else?

I am very interested in finding this out too. I have a pair of 496 mags that I wouldn't mind getting a little more hp out of.

Thats about it cam and computer and warranty.

HO's having cast cranks?, not as of 03 models. Where merc get's there blocks

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

HP1 496mag 375hp (CAST)

HP2 496HO 420hp (steel)

HP3 496 525hp (cast)

SuperCharge It
 

I have a 496 mag with a stage 2 program from whipple and a 5 psi procharger kit gained 12 mph. Very happy with the 496 mag.

So has anyone ever tried the cam and ECU modification? Do you know anyone that has done it?

I think Dustin said his cam kit should be ready in about a month.

Who in their right mind would pay 5 grand for a bbc crank.

Merc parts list 2 crankshafts for the 496 Mag. HO. One is forged and the other is cast, the same part number as the Mag.
They are identified by the casting number stamped on the engine..T10153XA for the forged crank and T10163XA for the cast crank. So, it does appear that they switched to the cast cranks in the HO models. Part number for the HO cam is 881628.

Bob

Just Once, If the above is correct, I say everyone who has a 496HO.

Bill