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1970-1995 Range Rover Classic
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Discussion Starter #1
I'm looking to do my head gaskets soon. Not leaking yet, but I'd like to do them before I have an issue. The truck is an early VIN 1988 NAS 3.5 with 110K miles and I was looking for advice on three things that I keep seeing mixed reviews on. Any help is appreciated as always!

First, Tin vs. Composite head gaskets and intake gaskets

Second, torquing all head bolts vs. not torquing the outer bolts (either present and tight or omitting them completely)

Thirdly, replacing the heads completely with rebuilt 3.9 or 4.0 heads, and if that was possible what to add/delete/prepare for

Looking forward to your input!
 

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What makes you think they are going to be leaking soon? Have you over heated your engine?

1: Gasket type is a personal choice. There are pros and cons to each and the topic is very well covered in existing threads.

2: It is not an issue of not tightening "outter" bolts. Older heads have four extra "lower" bolts. Head gasket kits no longer take them into account and are designed for only the main sealing bolts around the cylinders. You can leave them out or put them in for looks.

3: Folks have "upgraded" but very few people notice a difference. Parts to rebuild your current heads are readily available.
 

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1970-1995 Range Rover Classic
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Discussion Starter #3
Haven't overheated, but it definitely runs hotter than I'd like when running higher speeds, and I'm having issues accumulating air in the coolant over time. Plus I figured with the age and mileage it wouldn't hurt to be proactive
 

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Accumulating air? It's a sealed system. If you are getting air in the system you have a leak. Air in the system does not allow the system to get up to full pressure thus the reason you are running hotter. This sounds like a much easier matter of finding the leak. Any smell of antifreeze in the cabin? Has your overflow tank cap ever been replaced?
 

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1995-2002 Range Rover Classic
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have your radiator rodded by a radiator shop, not an in house drain and flush, replace your tank cap and thermostat. heads are interchangeable among all engines, the benefit to the newer head is the redesign of the valve stem, stronger valve guides and seats, as stated above the newer heads omit the lower row of bolts as does the newer composite head gasket even when the original heads are used.

I have always had difficulty locating the tin gaskets thus always upgraded to composite when working on the 3.5, as stated above don't go pulling engine apart on a whim, solve the heat concern first. the 3.5 although underpowered it is a robust torque filled machine which when well tuned it will keep up with a 3.9 in performance.
from then on it is up to the end user how far to undertake an upgrade, but that is a different conversation altogether.
 

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1970-1995 Range Rover Classic
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Discussion Starter #6
Recently I've replaced the radiator, cap, all coolant hoses, thermostat, heater core, coolant temp senders as well. Flushed the engine twice. Water pump was replaced by the PO 2 years ago. It runs just below half most of the time, runs at 3/4 after driving and especially going up any hill.

EDIT: unless what's happening is normal...I was trained by my Disco II to be gauge paranoid :lol:
 

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1995-2002 Range Rover Classic
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have you used other than the cluster gauge as a guide? non breathing engine i/e clogged cats or mufflers will cause an engine to run hot, is your fan clutch ok?, auxiliary fans?
 

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1970-1995 Range Rover Classic
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Discussion Starter #8
Fan clutch definitely kicks on. I can idle all day at 1/2 needle. I’m using the dash gauge only as the indication


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Discussion Starter #9
Aux fans work as well, I was thinking of removing the cats, in NJ we have no emissions inspection on 25+ year old vehicles


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1970-1995 Range Rover Classic
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Discussion Starter #11
have you used other than the cluster gauge as a guide? non breathing engine i/e clogged cats or mufflers will cause an engine to run hot, is your fan clutch ok?, auxiliary fans?
95classiclwb hit the nail on the head as far as clogged cats. Removed them and not only does the truck have things like throttle response and the ability to drive up hill, the temp needle barely hits the halfway mark now. I appreciate the info from you guys as always!
 

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There is a difference in the heads! the later heads 4.0 with composite gaskets from the factory have a different cc head volume. to make up for the thicker gasket. if you use composite head gaskets on your 3.5 with the factory heads you would need to shave off the difference to maintain compression. also head studs from ARP are far easier to put in correctly and don't run the risk of cracking block near cylinders 2 and 3. they are reusable as well. they make 2 different head stud kits, one for the 3.5 and one for the 3.9, 4.2, 4.0 engines the length is the difference! my 94 classic uses ARP and have had no issues whatsoever. with composite gaskets, mine were originally tin.
 
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