Zero at TOP DEAD CENTER / TDC.
Yes
NO they are not.
your truck does not have a bypass connector
GMT400 - 88-98 C/K 1500 (Silverado) GMT410 - 92-99 Suburban GMT415 - 92-94 Blazer GMT420 - 94-99 Tahoe
The 4L60E
NO, it has a timing chain.
That requires a timing light, you loosen a bolt on the distributor and turn it a little until the marks on the main pulley match a notch that you aim the timing light at.
Yes they are the same transmissions. Direct swop.
3.48"
No
if the specs are the same as they are in '94 which I wouldn't see why they would change them it's 0 degrees btdc.
It can be done, yes.