I just bought a donor 64 Newport that has a complete 3 speed setup. I bought it to put into my 61 Newport. BOTH car’s 361s are garbage.
So, I have a 1968 383 that runs excellent. It just overheats after a short drive. Pressure and antifreeze boils out of top of radiator. I changed water pump, thermostat with housing, and even tried an aluminum radiator. Same result. I think I’m going to remove freeze plugs and clean flush and then reassemble with new plugs and head gaskets.
The other major problem is that the 383’s automatic crank’s cavity is slightly too big for the new 5.2/5.9 bearing that guys tap in to support the manual transmission’s input shaft. I’ve done this modification before using a 1966 (auto) 440 to mate to a 4 speed. I had to actually tap this bearing into the crank cavity until it was seated. But again, my 383’s crank cavity seems just too large for the bearing as it slides right it without having to tap it in.
Additionally, I compared my old 361 with proper drilled crank to the 383. The 361’s crank is drilled a good inch deeper than my 383’s. This is no doubt because of the manual vs auto crank. So, the 383’s crank cavity is too big for the bearing AND it likely isn’t drilled deep enough to accept the 3 speed’s input shaft.
Anyone ever do this 3 speed swap in lieu of an automatic? Or, if you know of a thread, PLEASE let me know what you had to do to make it work. Thanks!
So, I have a 1968 383 that runs excellent. It just overheats after a short drive. Pressure and antifreeze boils out of top of radiator. I changed water pump, thermostat with housing, and even tried an aluminum radiator. Same result. I think I’m going to remove freeze plugs and clean flush and then reassemble with new plugs and head gaskets.
The other major problem is that the 383’s automatic crank’s cavity is slightly too big for the new 5.2/5.9 bearing that guys tap in to support the manual transmission’s input shaft. I’ve done this modification before using a 1966 (auto) 440 to mate to a 4 speed. I had to actually tap this bearing into the crank cavity until it was seated. But again, my 383’s crank cavity seems just too large for the bearing as it slides right it without having to tap it in.
Additionally, I compared my old 361 with proper drilled crank to the 383. The 361’s crank is drilled a good inch deeper than my 383’s. This is no doubt because of the manual vs auto crank. So, the 383’s crank cavity is too big for the bearing AND it likely isn’t drilled deep enough to accept the 3 speed’s input shaft.
Anyone ever do this 3 speed swap in lieu of an automatic? Or, if you know of a thread, PLEASE let me know what you had to do to make it work. Thanks!
