706 & 862 Cylinder Head Help

[bsch04av]

So after hours of researching, I have found that I have a passenger side cracked 706 Castech head.  I have slow coolant loss, no overheating, oil on dipstick looks good, but after taking my valve cover off, I noticed the peanut butter color sludge on the underside.  I'm trying to fix on a budget, so I only intend on replacing the passenger side head.  However, I would like to use the 862 head that is supposedly more reliable.  Does anyone know if these two types of heads can be mixed and matched?  Or would it be wise to stick to the same type of head on both the driver and passenger side?

[SierraHD17]

The heads are identical in port, chamber and valve size and can be interchanged with one another.  Running one 706 and one 862 is perfectly fine.