Will a RV8 3.9 cylinder head fit to a 3.5 engine?

[LandRoverNut]

I've an old RV8 3.5 with worn vlave stems, and been offered a pair of 14 bolt 3.9 cylinder heads. Will these fit, and if so is there anyother issue I should be aware of, such as gaskets etc.

Is there any performance benifit from fitting 3.9 heads?[/i]

[ChrisJC]

What is the engine?, as there are a few variations of 3.5 heads.

Chris.

[sidecar]

They will fit, as to performance improvement, it depends on how old the 3.5 heads are. The first ones had slightly smaller valves then the later ones, I doubt that you would notice much difference though. Of course you could do some work on the 3.9 heads before you fit them, that way you will notice a difference.

[LandRoverNut]

Thanks for the information, my engine is from a range rover, number 11D 00036A, which dates it between 1970-83 I believe.

As yet I'm not sure which is the best way to sort out the smoke on overrun, I found mention on this forum of using Opel Manta valve stem oil seals, although my original idea was to refurbish the existing heads.

How easy is it to swap the valve guides, I see RPI do a head overhaul kit, is this something I can do in the garage, or does swapping the valve guides involve a press etc.

[DEVONMAN]

Thanks for the information, my engine is from a range rover, number 11D 00036A, which dates it between 1970-83 I believe.

As yet I'm not sure which is the best way to sort out the smoke on overrun, I found mention on this forum of using Opel Manta valve stem oil seals, although my original idea was to refurbish the existing heads.

How easy is it to swap the valve guides, I see RPI do a head overhaul kit, is this something I can do in the garage, or does swapping the valve guides involve a press etc.

Smoke on overrun can sometimes be due to worn oil control rings.
Does the engine use any oil ?

Cheers
Denis

[ChrisJC]

You might find the ancillary mounting holes are different between your 3.5 heads and 3.9 heads.

Chris.