1991 Cadillac Allante Spark Plugs

You have to remove the intake manifold at the top of the engine.........

My understanding is that the engine cradle has to be loosened and lowered to gain access to the rear plugs. I have never heard of having to remove the intake manifold for access. While neither option is great, lowering the engine eliminates the need for a new intake manifold gasket, proper torque sequencing of the intake manifold bolts, etc.

PUT IT UP ON A LIFT ACCESS IS SIMPLE.......AAACAR

on my 89 Riviera, i was lucky enough NOT to need to tilt the cradle. i just used a deep socket and 3/8 drive ratchet but that was a 3.8L V6. V8 could be a different story. those years had more space than 2000 model years.

You will be able to get to the # 2 and #4 plugs from underneath the vehicle. It requires a lot of patience and long skinny arms, both of which I lack. lol