3.9L V8 Heads on 3.5L Block - Which Head Bolts to Use?

**Old Farang** · 22nd June 2019, 01:40 PM

I can't remember how much thinner they were, but it could be measured using a ruler. From memory they are 10 bolt heads.

The original OEM thickness is as follows: (10 bolt)

Suffix B and on:

A=22.94 mm/ 0.903”
B= 62.55 mm/ 2.463”

Land Rover recommend amaximum of 0.5 mm / 0.020” should be removed, but from many enquires I havefound some that have had 0.070” / 1.778 mm removed without a problem

Don't know what the cc capacity is, but will vary if the heads have been resurfaced.

**PhilipA** · 22nd June 2019, 06:53 PM

Just to be clear the 3.9 heads are identical to the 3.5 heads except for waisted inlet valves and the deck height. I had a 91 3.9 RRC and took 40 thou off the heads and fitted composite gaskets.

I fitted a set of 4.0 litre new heads that I bought and they were the same also. Except AFAIR the holes for the aircon bracket were smaller or larger.

All ( most) Rover engine parts are backward compatible.

I found the last of the heads were worse in the casting of the ports than the earlier heads with a BIG step in the exhaust port.

I have not found that the heads warp at all and I have never heard of a cracked V8 head. The worst that happens is that the exhaust valve can jam from carbon deposits and the inlet valves also get gummed up. I fitted the later seals to mine and did not seal the exhaust valve.
Regards Philip A

**I Love My Landy!** · 23rd June 2019, 05:52 PM

Thanks Old Farang and PhilipA

Thread: 3.9L V8 Heads on 3.5L Block - Which Head Bolts to Use?

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