Hi all, new member here.

I just purchased a 2005 Impala 9C1 from a police department. It is a 9C1 police package car with the L36 engine and the M15 4T65 transaxle with the FR9 3.29 output ratio. I haven't found the RPO sticker, but got this information through a website that can pull this information up from the VIN.

Even thought the listing initially said the car ran good and was retired for a newer vehicle, it turned out to have a rod knock that wasn't posted in the auction listing, even though it was documented in the car'* service history (yes, they gave me one). Of course, the auction website has been absolutely no help in this. They supposedly contacted the seller requesting them to contact me, and I have, of course, heard nothing.

I had actually changed the oil with 20W50 and Lucas to quiet the knock to get rid of it through an auction and try to at least get back the $1,000 I paid for it. Shady, yes, but I'm sure anyone could understand wanting to get rid of it when you get burned right off the bat.

However, reviewing the service history further has revealed that the transaxle was replaced 25,000 miles ago, and the power steering rack, power steering pump, wheel bearing hubs, brakes and tires were all replaced in the six months prior to the car being retired. So, it appears as though the engine is the only major thing really left to replace. Got me wondering if it might be a better idea just to fix/replace the engine.

And therein lies the rub. I have found a screaming deal on what is supposedly a 1997 3800 long block that was never installed in a car, but I am getting conflicting information on what years of 3800 will work in my Impala. I also have not confirmed whether this engine is a RWD or FWD block. The seller says they have been told it is FWD. A local GM dealer has told me the original engine is basically a RWD 3800'* innards in a FWD block, and has told me the same interchange information as the salvage yard -- 2000-2005.

However, I have cross-referenced a majority of related parts to a 1997 Buick Regal. Mounts, cam/crank/knock sensors, intake manifold, torque convertor part numbers all cross-reference to a 1997 Regal. The Series II section of the Wikipedia article on the 3800 shows the LeSabre used this same engine from 97-05. On the surface, it appears that this swap will work. The GM dealer confirmed that certain applications had only external differences such as oil filter adapter, etc.

I'm 95% convinced that this will work, but I need to know how A) I can confirm that the engine I have my eye on is a '97 FWD block, and B) I can confirm that it will indeed work in my '05? Is it simply a power difference? Were the L36s all the same from '97-05 as my cross-referencing and research indicate, or was a major change made in 2000 that will not allow a 97 engine to be used in an 05 application?

Thanks in advance for any help, this car rides and drives nice and it seems a shame to send it to the junkyard with all the work that'* been done to it. An auction buyer will likely just junk it when the engine blows, and if I can get this car straight for $1,800, I just got myself a practically new car for under $3,000.

I don't see why it wouldn't work.....go for it or cut your losses and move on.

You can many times look for a series 3 block as well. The blocks are all the same as I understand it, it'* things like oil pans, sensors, brackets, etc that changed around, so you will need to look and see what needs to be switched over.

Also, you will want to be sure that any intake manifold issues have been addressed on the new engine before putting it in.

should work I think

What web site did you use to get the information from the VIN