[locomotivebreath]

The 400 in my 68 GTO was original down to the thermostat when I pulled it for a rebuild in 2012 . My dad parked the car in the 70s . I had the original starter , water pump & altenator rebuilt . The timing cover & thermostat housing were corroded through however .

[Judas]

Pretty sure mine was original when I cracked it open after my wife reduced the rotating assembly into random chunks of metal (early 2000) The machinist said he had to bore it to the unusual size of .40 to get out the scouring, grind a small section where a piece had been knocked out of the bottom of a cylinder bore (plus, of course mag checking) and the heads needed "everything". I had them install hardened valve seats on their advice- I recall him saying the valves were sinking into the heads because someone wasn't adding lead to the fuel for a long period of time.

2200$ later, I had fresh heads and restored block with bearings, bored .40 over and the pistons bore matched on their rods, etc.

All in all, I feel that its safe to say this motor was original.

[geeteeohguy]

Last year I helped a forum member here reseal the 68,000 mile original engine on his '69 GTO. The most original, unmolested engine I've seen since about 1979. Had no visible wear on the bearings, crosshatch in the cylinders was good, etc. We replaced the core plugs, rear main, pan gasket, timing set, and put it back in the car with the Cliff-redone original carb. The car still doesn't have 70k miles on it and rides like a new car. Been into a lot of Pontiac engines, but have never seen one this virgin.