Re: 2002 Jeep 4.7 HO Engine Swap now will not start Sentry Key light stays on
First the easy part, the ground straps are mounted underneath both aft ignition coil nuts ( #7 and #8).
Now the difficult part: did you double check that all connectors are connected right and that no fuses are blown?
The problem could be sentry key related, however normally the engine would start and shut down after 2 sec. If you could use a DRBIII scanner, you could find any Sentry Key system faults.
You are sure that both the old and new engine are exactly the same?