1971 mercury comet engines

What motors came out in mercury comet?
I have a straight 6 3 speed auto, have pulled motor down trying to track new piston down as one is cracked. The valve cover days it's a 200ci but my registration of the vehicle says it's a 4.1. My piston is the same as a 4.1 250ci in width but the height is a mill or so bigger on the 4.1 250ci to my piston. The rod on my piston is a lot smaller than the 250ci

Any help much appreciated

 

Attached is few pics. It is 3 bolt water pump and that's length of piston. So what cc is the 200 and 170?

 

The only markings it has says 250 on the side of piston.
My motor has the 3 bolt water pump, 7 mains, and 5 frost plugs on exhaust side which I think determines it's a 200ci.

Might have to take it into a shop to get them to nut it out haha.

 

Here's a pic of the number

 

Here's pic of top/side no numbers

 

Another question what motors bolt to the original 3spd auto? Are they same as v8?

 

I don't think a stock piston has a bore size stamped on the top...

 

why do you even want to keep the 6 and the expense of building it...

 

Wanting to keep it original to get it back on the road will change engine at later stage

 

Trust me there's nothing on there haha

 

3 bolt starter motor yeah. Just measured the bore size and stroke and it measures up to the 200ci engine size

Cheers for that!

 

I do know I think that...

 

200 and 250 used the same piston. The pre-'72 has a 6.5 cc dish and '73-'83 have 6 cc dish. The '66-'67 California Emissions 200's had a 13 cc dish.

 

P

Can I use pistons with no dish in it?

 

You can but a dish piston in a wedge type head will make more hp than a flat top. Piston to valve will need to be checked and double checked. The cost of custom piston will be up there too. The guys over on fordsix.com will be more help on this subject.