I must confess that I thought that all the 'rubber bumper' USA versions on the bonnet had the rams fitted. Mine certainly did; a December '72 car.
The first thing that you need to do is to find a pair of UK spec bumpers and overridders. I found some new-old-stock at the Jag autojumble at Stoneleigh, but that was 10 or so years ago.
The old US spec bumpers and rams just unbolt leaving a hole about 4 or 5 cms in diameter. That just get plated and filled / lead loaded....you can see the extent of the work in the picture of mine being done.
Then just offer up the new bumpers. My new-old-stock ones fitted perfectly, but my car had never had a bump so everything was as per factory. The chances are if you are using repro bumpers or the bonnet has had other repairs in its life, then the bumpers will need to be shaped to fit, and / or the bonnet may need some work to enable the bumpers to fit. That can start to get expensive, hence why I paid more for original bumpers rather that repro.
Alan Proctor did the work, and from memory, the welding / lead loading took 6 hours to complete.
The big job is then the re-painting, as the whole top of the bonnet (at the least) has to be re-finished as there are no swage lines or panel gaps to paint up to from the repaired hole. Just doing the top of the bonnet will work if you have good paint on the wings and the rest of the car, otherwise it will stand out as a repair. My car needed a full bare metal paint job as the Californian sun had burnt it through.
So for me, the job cost less than ?500 for the new bumpers and the metalwork, and ?8000 for the re-paint......but that was the whole car!
And the result is Primrose Perfection!
