We have disassembled 12 Perkins 4.108's so far this year and have 4 more in the shop. Sometimes it is easier if you remove the head studs, but you need a proper "stud remover". We use a Proto Stud Remover. Otherwise do as previous readers have suggested.
If you admit defeat, ship us your old 4.108 and we will rebuild, re-man or repair it and ship it back. Our price
for a total re-manufacture of a 4.108 is $5,995 LONG BLOCK + shipping
and possible other costs, like grinding a damaged crankshaft, replacing tappets and camshaft, maybe even rebuilding the injector pump
Okay, we are somewhat biased, but we believe the Perkins 4.108
is one of the best diesel engines ever built. Otherwise why would
Ma Perkins have built over a half million of them? Our re-mans go over 10,000 hours with proper maintenance
Hope this helps. We are booked up until March 2015.
Tom at BSH Marine
, Bayou Chico, FL