Hello

[srbranger]

Hello, I am Steve, I have a 1995 Explorer and a 2000 Ranger both 4x4 both 4.0 both XLT's. My grandparent's worked at ford in Dearborn Mich. so I have fords in my blood. My question is can I replace just 1 head the # 3 exhaust valve is bad. Two mechanics tell me I should replace the bottom end because the rebuilt head will blow out the bottom end because of the higher compression it will have. Is this true? Thanks Steve

 

[Joe Dirt]

First place I would start is by getting compression readings from your current setup. If it is just the #3E valve, why not just replace #3?

(and welcome, Steve!)

 

[Sams01XplrSprt]

welcome steve

 

[BrooklynBay]

Welcome to this forum! You could examine the other internal parts to see if they need to be replaced once you open it up to replace the valve.

 

[Dopler174]

4.0 OHV is a strong bottom end. Unless the compression is low, I would fix that one head and probably get the other one worked while your at it. (It could go bad as soon as you put it back together.)