Bore out cylinders?

[Luke94]

So i just tore into my engine, removed the heads thinking the reason for my running problems were a cracked head or bad valves. Looking like they are not the issue but instead maybe piston rings are bad. What i am wondering since i have this torn apart and will be pulling the block out of the rig here soon is has anyone ever bored out a 4.0 OHV engine before and had noticeable gains? Is the money worth it in other words. Thanks for the feedback!

 

[RonD]

Really can't go much bigger on the bore.
The 4.0l block started off life as a 2.6l, then 2.9l, 4.0l is pretty much maxed out.
You can get Stroker kits to make it a 4.3l, but close to $3,000, and adds 30HP, for that kind of money you can drop in a 5.0l and get 50HP bump, and the 5.0l's have alot more upgrade potential

 

[RangerSVT]

I agree with Ron, if it needs more than 0.010", replace the block...

SVT