Ran into a snag dyno tuning the 4.8 swapped C10. I used the TH350 and, for dyno tuning, have left the kickdown disconnected. (Vacuum modulator is plumbed up, though.) While trying to hold it in second gear past about 70% load, it will run for a couple minutes, then start slipping horribly and won't stop until it's sat for a while. Shifting it into Drive does not get it to engage at this point - it acts like it's in neutral when this happens.
Does this sound like the transmission is shot? Just plain needs a cooler? Or is trying to run close to full power through a TH350 for a long period of time asking too much of it?
Doesn't the kickdown effect line pressure, and thus, how hard the clutches will grab?
How's the governor?
It very well could be on it's last legs..... Easily rebuilt in a sandstorm with noting but simple hand tools. I'm betting on the apply piston seal is worn out causing the slip.
TH350 doesn't care about the cable- I think. The 700's use the cable for throttle pressure because they have no vacuum modulator, so it needs the cable working correctly.
I'd consider hooking a wire up to the lever so I could reproduce full throttle just to see if it makes a difference.
Thanks so far - any sort of testing I can do without opening the pan, like maybe testing the fluid temperature?
