250 Pro XB heads

[Freedom92]

What are the casting numbers for 250 Pro XB heads. A guy is trying to tell me it is C-2. That's what I have on my 2002 225 efi. Is he full of it or are they actually better heads than the ones I already have on the motor?

[moldman]

I think it is C-11 for XB and C-10 for Pro Max. C-2 is standard 225 head.

[Freedom92]

That's what I'm leaning towards too. This guy is trying to pass off C2 heads as Pro XB heads and they are the same ones that my EFI 225 has.

[moldman]

C-11 heads have 65-67 cc, C-10 has 63 cc per Chaz on this site. C-2 has 73 cc but I have personally seen them with 78 cc.

[Freedom92]

Thank you sir that's very helpful

[Freedom92]

C-11 heads have 65-67 cc, C-10 has 63 cc per Chaz on this site. C-2 has 73 cc but I have personally seen them with 78 cc.

The guy is actually trying to tell me there is no difference in 225 C2 heads and 250XB heads. Says even 300 ProMaxs are the same as the 225 EFI

[moldman]

Don't believe him. They are different.

[Freedom92]

If they weren't different there would be no sense in different casting numbers. From what I've read there's little to gain by surfacing these either. Better to get ProMax or Pro XBs to start with.

[Chaz]

C-11 heads have 65-67 cc, C-10 has 63 cc per Chaz on this site. C-2 has 73 cc but I have personally seen them with 78 cc.

Did the 78's come off of a 25" or 30" mid section .. 200 hp work mule ?

[moldman]

They were on a 2000 225 20" mid that I got hold of with a bad crankshaft. I think it had a replacement power head on it as it did not have the serial no. plug in it. The reason I think it was a factory powerhead was after I pulled a head to look at the bores and measured them they measured 3.6265 and the crosshatch looked great. It also had the bleed line system like the 95/96 225(according to merc manual). I gave it a light hone and put a different crank and fresh rings, ran it a few hrs and checked compression. It was 95. So I pulled a head and cc'd it and it was 78cc.