The biggest engine you can fit in a probe is the engine out of the Ford Taurus SHO. I believe it is either 3.0 or 3.2 and requires a lot of modification to fit.
According to the 2003 Ford Windstar Owner Guide : ( 5W-20 ) * With engine oil filter change , the 3.8 L V6 engine takes ( 5.0 U.S. quarts /4.7 litres of 5W-20 )
According to the 2002 Ford Windstar Owner Guide : With engine oil filter change : The 3.8 liter V6 engine takes : ( 5.0 U.S. quarts of 5W-20 )
I was looking at the 2001 Ford Windstar Owner Guide and it shows : With engine oil filter change : ( 5.44 liters of 5W-20 ) * but the 2002 and 2003 Ford Windstar Owner Guides show 4.7 liters of 5W-20 is used *
According to the 2002 Ford Windstar Owner Guide : With engine oil filter change : The 3.8 liter V6 engine takes : ( 4.7 liters / 5.0 U.S. quarts of 5W-20 )
According to the 2002 Ford Windstar Owner Guide the 3.8 liter V6 engine takes ( 5W-20 engine oil )
The Ford 3.8 liter V6 engine in a ( 2001 ) Mustang and Windstar models : Takes ( 5W-20 ) * With engine oil filter change , 4.7 liters / 5.0 U.S. quarts of 5W-20 )
On a 1998 Ford Windstar : GL / 3.0 liter V6 engine ( 20.0 U.S. gallon ) GL / 3.8 ( 20 or optional 25 ) LX /Premium Package ( 25 )
On a 1998 Ford Windstar : ( # 16 / 20 amp )
This question cannot be answered until the year and engine size are corrected (the Windstar was introduced in 1995 and they never had a 351 or 3.5l engine.) In the meantime - the process of replacing head gaskets is way too complicated to be specifically answered here. This would require having a shop manual, or pages for the procedure from a shop manual. Manuals cost less than $20 at any autoparts store. Libraries carry these manuals too, so you can copy the pages for about $1.
I was looking at the 2002 Ford Windstar Owner Guide and it shows : ( 5W-20 is recommended )
According to the ( 2003 ) Ford Windstar Owner Guide : With engine oil filter change : The 3.8 liter V6 engine takes ( 5.0 U.S. quarts of 5W-20 )
A ( 1996 ) Ford Windstar GL either had a 20 gallon tank or the optional 25 gallon tank