If this should be under technical, I apologize. I didn't think my question is technical enough for that section.

I just bought an 86. The V6 has a bad knock and leaks oil badly. I am planning to go to a 3.4. The easiest, according to those of you who have done it, is to put in the 3.4 from a 93-95 Camaro. Some of you have noted that these engines are getting harder to get. From Wikipedia's article on the 60 degree V6 is this:

LG8

The LG8 was a modern version of the 3.1L engine, produced since model year 2000[citation needed]. It still had an iron block and 2-valve pushrod aluminum heads but now had full sequential port fuel injection. The LG8 also featured a new intake manifold and numerous changes to improve parts sharing with the offshoot GM High Value engine family. Emissions were improved with air injection for LEV status. Power was 170 hp-175 hp (127 kW to 131 kW) and torque was 190 ft·lbf–195 ft·lbf (258 N·m to 264 N·m). The LG8 was built in Ramos Arizpe, Mexico and Tonawanda, New York.

Applications:

* 1999-2003 Pontiac Grand Prix
* 1999-2005 Buick Century
* 1999-2003 Chevrolet Malibu
LA1

The LA1 3400 was a bored-out version of the LG8. It retained the OHV layout of the previous engine, and was first utilized on the 1996 U platform minivans and appeared in a car for the first time in the 1999 Pontiac Grand Am and Oldsmobile Alero. A 92 mm bore brought the displacement to 3.4 L (3350 cc). Like the LG8, the LA1 featured numerous common parts with the similar GM High Value engine family. Power was up to 170 hp-185 hp (127 kW to 138 kW) and torque was 210 ft-lb.

It is used in the following:

* 1996 Chevrolet Lumina APV/Pontiac Trans Sport/Oldsmobile Silhouette
* 1997-2004 Chevrolet Venture/Pontiac Montana/Oldsmobile Silhouette
* 1999-2004 Oldsmobile Alero GL/GLS
* 1999-2005 Pontiac Grand Am SE/GT
* 2002-2005 Pontiac Aztek/Buick Rendezvous
* 2000-2005 Chevrolet Impala
* 2000-2005 Chevrolet Monte Carlo

If the bellhousing bolt pattern is the same, and I have no idea, why would the LA1 not be a good choice? Or would it? I assume that getting whole donor car would be a good idea. Some, or all, of the engine related wiring will need to be changed, won't it?

I had the Alero version of the engine in my Alero 2 door. The engine really is a good performer. The one problem is head gaskets. If the engine hasn't had them replaced before you buy it, then replace them before you install it. Other than that, it goes great. One other thing, the reason I sold the car was that the auto tranny developed a shift valve problem and I was talking major bucks to pull the tranny. If I was installing one, I'd go with another tranny other than the one used in the Olds, especially if you plan spirited driving.

Arn

LA1 is a big improvement from the stock 2.8. I did the swap back a few years ago when it was a new idea and only a handfull of people where doing it and each person was doing it differently. The only real problem with the 3400 is the lower intake gasket. Up until 2003 I believe, they were none to go around 80000 kms. 2004 year they finally go the gasket right and fixed the issue. Dexcool eats away at the plastic gaskit slowly, I've been using antifreeze since I did the swap and haven't had any issue with my 3400. This motor is a good choice it you don't crave the power like a 3800 S/C, want something a little more simple to do, and just want something different from everyone else I chose this motor for the reason I could do the swap mostly by myself with the help of a friend who programmed the ECM and did the exhaust. I'm using an ECM from a 3.1L cavalier (OBD1) there is HP Tuners now that you can keep it OBDII and use it to program the ECM.

Anymore question, feel free to ask. I've done 2 3400 engine swaps and each one is completely different set-up

Is this swap more or less a bolt-in, then? What are the major challenges? Should I search for 3400 swap threads here?

To paraphrase Will Rogers, I don't know anything about GM engines I don't read on the 'net.