|
Anders, Dimensionally, the crank is the same. Whether or not the part number, and the hardening process is the same, I really can't say. The 7000's rods are drilled to supply cooling oil to the piston. The 5000's are not. The 7000 has heavier pistons, and quite likely a larger swirl chamber, as the compression ratio is lower. The heads may have different numbers.... But I'd bet they are darn close to the same on both, with ONE exception. The 7000 will have a different grind angle on the valve seats. As above, the valves are different, possibly in hardening on the 7000, and definitely the grind angles. The 7000 will have larger injector nozzels to deliver more fuel. The 5000's tips would likely max out before you got to that level of fueling. Pump would be identical, with the exception that the big screw is turned out a little further on the 7000.... The rod bearings are different in that they are drilled to supply oil up through the rod on the 7000, and not on the 5000. Otherwise, babbit is babbit.... The cam would certainly be different to take advantage of different breathing and exhaust patterns, and develop torque at the appropriate speeds. The early 256T's used full flow, constant pressure turbo's. The later 256T's, after '79 or so (blue power specials) used a twin inlet, pulse turbo. Hence, a twin inlet turbo will require a different exhaust manifold. The 5000 and 7000 would still have different manifolds for mounting the turbo.
I would also expect the 7000 to have a larger volume oil pump to cope with the piston cooling. Also take note that the 7000 had a heavier back end. The transmission was beefed up some over the 5000..... although the 5000 was quite stout to begin with.
There's probably more differences than that, but those would be the basics.... HTH. Rod
| 
