I had a similar problem and way beyond my mechanical ability plus time. The cause was my fault. Our own mechanic, who is exceptionally good, was not well at the time and I could not find anyone locally to me in Essex to do the job. In the end Gary Rigby (80 Breaker) sent a truck to pick up the vehicle. He supplied an engine from a 100 series, swapped all the ancillaries from my 80 series engine to the donor engine, new BEBs and other things checked out. Engine installed with new clutch kit. It was expensive but I could not have replaced the vehicle in that price.
I must admit after sending the truck up the road I read negative comments online about Gary and thought WTF have I done. Gary kept me informed with progress and sent me photos. He had a very clued up mechanic working for him. Gary phoned one day to say they could not start the new engine. It was the poxy immobiliser playing up. One sorted he was very disappointed with the performance and asked me what it had been like before ( it is a 95 24 valve ). I said crap compared with the earlier 12 valve we had owned. Well between them they tweaked it and it improved the acceleration tremendously without knocking the fuel consumption. It runs without a puff of smoke. When I collected it from Gary's yard near Wisbech, my mate followed me home and could not believe how quick the old thing is! From my perspective Gary was not cheap but he sorted out the truck when I was stuck locally. He is blunt and is in business, which some seem to forget. The old 80 is still useful, has not done many miles a year since the engine swap in 2021.
