I was not clear. I meant ignition timing, not cam timing. BTDC = before top dead center, ATDC means after top dead center. The 3.5 has a crank position sensor, and I don't know if it's adjustable - never did mine while I had it. I'll go look at the 3.5 manual and let you know. I trust the cam timing is correct or real close. I don't remember if the 3.5 has a cam position sensor, or how the ignition is actually timed.

Edit: The timing is not adjustable, but should be 5*btdc, +/-3*, with the brown single wire timing check connector on the firewall grounded. timing connector should be near the heater hoses, single wire into a brown connector which may have a sealer on the connector. Ground the wire inside the connector to a good ground - engine metal is good. Use a timing light to check the timing at the crankshaft (I think - manual is not clear)

IF the idle is stable and power is still not there, does it misfire as it tries to rev up, or just no power?