Will a 1993 Buick 3800 engine fit in a 1994 Pontiac Bonneville that now has the same 3800 engine or looks the same? Please let me know what has to be changed, if any thing? Thanks, Marge.

EGR and associated tubes
CPS and crank pulley
MAF
Knock sensor locations (maybe)
I think the O2 sensors

Supercharged or naturally aspirated?

I want to drop the Buick engine in the Pontiac, it'* not a supercharged engine. Are you saying these items I have to change from my engine to the Buick engine ? EGR and associated tubes
CPS and crank pulley
MAF
Knock sensor locations (maybe)
I think the O2 sensors
Thanks, Marge.

Yes, you'll need to keep those items from the original engine and put them on the 93 engine.

Thanks J, if you think of any thing else I may have to swap please let me know. Thanks again, Marge.

In other terms (but saying the same thing) swap in ONLY the hard big parts. Block, heads, and manifolds.

Keep everything else (pulleys, accessories, sensors) from your old engine.

EGR and tubes - Yup. Two different setups.

CPS and Crank Pulley - If you mean the crank/cam sensors and the HB, no they do not need to be swapped. If it were a 92 engine, then yes.

MAF - Yes on that one too. If you have the complete engine to swap in (intake manifold and throttle body attached), all you need to swap in is the MAF sensor.

Knock sensor locations - L27 to L27 are the same locations (up front, above where the oil filler tube goes into the block).

02 - When doing a swap, I usually try to go for new instead of swapping. But yes, the O2 sensors are different in that the '94 uses a 4-wire setup.

Keep in mind there were *slight* internal differences, mainly in the piston rings and bearing design. Nothing that will keep you from using the motor if you already have it.

Any work going to be done to the "new" motor before getting swapped?

I will replace the valve cover gaskets, new spark plugs, oil filter and oil change, new thermostat, I also have a new water pump from my old engine. I guess that will be it ? Thanks for all the help, Marge.

There are no piston and bearing differences between 93 and 94 L27'*. The engine, internal rotating parts, pistons, heads, and entire valvetrain are identical in every way.

92 was a little different animal, but not 93/94. (or 95 in the case of the other GM cars and vans that took the L27 another year farther than us)