Straight Springs vs. Conical Springs
 

I have a 1999 Ranger FFV built in Semptember of 1998.

I was told by the machine shop that my heads (F6DE GA) cannot be reused or machined (outside of workable wear range) for cheaper than remanufactured heads.

I bought a pair of heads for National Cylinder Head that came in yesterday, but they have casting #F6DE GC indicative of smaller (7.0 MM) valves with conical valve springs. My original heads (F6DE GA) has the larger (8.0MM) valves and straight valve springs.

My question:

Will the conical valve spring head work on my (9/98) Ranger 3.0 even though it first appeared in the Ranger around 7/27/99? Can I still use the same parts (rockers, dowels, etc)? The reman company says they send these to people all the time and haven't heard of any problems.