PSlonaker,

Not trying to get into a pissing match but you are wrong. I am presently rebuilding a pair of Mercury 575 SCi engines. These engines are GenVI. Straight out of Merc Racing, there were Mark IV cams installed. I just had RMBuilder grind me 2 new Mark IV cams. I can assure you, the cams are Mark IV and fit these Gen VI blocks.

Vinny Did you have any problems with cover clearance using the mark 4 chain & gears inside the 6 cover?

PSlonaker, will all do respect, your totally wrong.

The reason there are 2 different parts #'s, is b/c the Gen6 motors have a stepnose, that works with the plate that BillK is taking about. All you need to run a gen6 cam in a MKIV block, is the Gen6 timing chain kit, that comes with a timing set, retainer plate, and bolts. Its like 60.00.

My friend is currently runing this setup, and it works great. Much better deal than setting up the endplay, etc.

racinfever,

Yes, I did have some trouble, but it was mostly due to my lack of knowledge in this set-up. This thread explains it..

http://www.offshoreonly.com/forums/g...chain-set.html

P,
You dont have to believe any of us here on the forum if you dont want to. Pick up the phone and call Crane, Comp Cams, Erson or your choice of camshaft manufacturer and ask them instead.

Afterwards please come back here and tell us what they said so that we will all know the correct answer to this question.

Bill Koustenis
Advanced Automotive Machine
Waldorf Md

I have a feeling we may not hear back from mr. lonaker....

You will hear from me...I dont turn tail and run a so many others do. I will look into this somemore, but I have always been told what I have said...it wont work and I will stick with that until I actually see it work. The basic difference in the cams is a step on the front of the cam on Gen 5 and 6 whereas the step is not there on a MK-4 cam. The step is for a retainer bearing, but not all blocks have the provision for this. I have both types of cams and a few motors, so just for fun I will stick one in and see what happens.

And...it is Slonaker...not lonaker

well some of the confusion my come from the fact they made gen V with a std flat tappet cams, and I believe some with roller, so that may be why crane list differnent part #'s, also just because they list diff #'s thats no proof that they still won't work...how many other times you have used a part with a # from something else....Rob

ok , if i'm getting this correct , if i purchase a gen6 cam for my mark 4 engine , i need to buy retrofit lifters , and the timing set for the gen 6 , that will have the retainer plate

Bill K , whats your direct e-mail ? i may need some machine shop services come spring time , and everyone says your the man around SOMD

I'll take experience over what a freakin' website says any day!