Sounds like a busted clutch fork or a collapsed flexi hose which can act like a one way valve....

Here's a link to a lovely collection of a dozen Series Land Rovers for sale here in Ireland. https://irelandmade.ie/ Just click on the Home tab on this page to get you in the right direction.....

I think you can upgrade a Series 3 heater box with one from a 90. I'm sure there is experience of this in this forum.

Don't waste your time with WD40. I've been using an aerosol of gun oil for years. It's a great corrosion inhibitor.

I'd suggest putting a mark at 8° BTDC and disconnect the vacuum hose to the distributor. Depending on the stretch in your timing chain you could advance it a bit more than that. It's easy enough to hear knock in Rover V8's. The timing marks on...

I had this problem before. One of the pins in the release mechanism cross shaft had sheared (it wasn't the proper part, just a bolt) and the piston in the slave cylinder had reached the circlip at the end of the bore. So no clutch release and a...

Your SU's have a sprung needle. They're not firmly centralised like a 1 1/4" SU.

Your carbs are plumbed with a return line back to the tank. It needs a restriction in the line down stream so that the fuel feeds to the carbs otherwise they won't receive fuel. I'd suggest checking the two 6mm nylon lines from your carbs...

The exhaust manifold to head gaskets you linked to are correct and are a good upgrade. The head gaskets are not correct in my opinion. You must use the OE metal sheet head gasket. If you use composite (3.9) gaskets you will lose valuable compression.

Go for P38 Range Rover exhaust manifold to head gaskets as they each cover two ports. Much less fuss than OE 3.5 gaskets which are easy to fit the wrong way round and are generally a pain in the ass to fit. Use only 20W50 oil my friend, nothing...

I forgot to mention that I use 20W50 in my vintage grease/oil gun as the EP140 was a bit smelly.....

The rubber outer sleeve on those connectors can be folded or slid back with some workshop spray, but don't try to twist both halves of the connector. Just pull them apart. There's a location groove inside them.

My vote would be either oil on the clutch disk, or a soft/broken engine mount on the front left.

Don't buy an aftermarket amplifier. An OE unit will last a long time. You can buy a cable extension kit to remotely mount it on the inner wing to get it away from the engine heat. I think Discos had these remotely mounted from the factory.

Forget the naysayers here my V8 compadre. Although your ignition amplifier is mounted to the distributor, it still needs a good earth, through its base contact with the distributor. Early amp units had one, (3 wire), and then they changed to two...

It will elongate if you pull it. Maybe splines are a bit tight.

While you have your distributor cap off, make sure your bobweight mechanism for ignition advance is free and working. If its seized or partially seized it will cost you horsepower.

Why did you need to fit HD shafts? Reason being my buddy snapped a rear shaft in a Puma 110 recently, but only moving off from standstill uphill. Not exactly a "tough" shaft..

I've fitted several V8's into Series over the years. The only differences I've seen with starters is the position of the solenoid. Range Rover/SD1 starters have the solenoid mounted to the side and MGB/Morgan V8's have the solenoid mounted below...

A friend of mine used a US company called Vintage Air when he fitted A/C to a vintage car in the past. No harm sending them an e mail.

I've seen this mysterious starting behaviour before. The Landy concerned had two bad segments on the the starter's commutator. This means a lottery when going for a fresh start, as it depends on where the motor stopped rotating the last time it...

Gearbox to engine nuts are 9/16". The top two are either 9/16" or 5/8".

You could try giving Shielder Chassis a call. They're in Armagh. They might be able to assist.