OK, back from just about 1250 miles of absolutely thrashing the car. What a blast! Car ran like a top, and I was anything but kind to it. The engine just sings when way up high, and as hard as this might be to understand, everything seems to feel alive and happy when running 10/10 at 4k+. The transmission shifts at 6700, and it feels like it would keep right on going (I like the rods where they are, though).

If you ever get a chance to travel to an event surrounding Tail of the Dragon/US129, the Cherohala Skyway, or any of the other incredible driving roads in this area of Tennessee, North Carolina and norther Georgia, DO IT! I have had the privilege of driving on roads all of the US, Alaska and many parts of Europe. While there are challenging roads, beautiful roads, and wonderful scenery in so many places, so few have all of it packaged together. So few areas have made their roads a tourism attraction all their own. The Crossfire event is run twice a year. Once in the spring, and again in the fall on the first weekend of October. Get in your car, and make plans. The Crossfire folks are some of the kindest and most welcoming "car guys" I have ever attended an event with. Cannot possibly say enough good things about them. Check the Crossfire Forums in the event section HERE to get info, and get your reservations in early. DO IT! You'll be glad you did.

At the event, the car became a point of a lot of discussion. More than one person commented that the M113K was too much engine for the car. They're not completely wrong, but they're also wrong. I did find the car to be much more of a handful to get through the corners than the 3.2L normally aspirated (N/A) guys did. The power comes on like a hammer, and is often hard to modulate, unless one is willing to leave it in a lower gear, and keep the RPMs up very high for many miles at a time (I wasn't). This resulted in a need for strategy to plan for wide open throttle (WOT) downshifts, and the resulting tire spin/back end boogie. The resulting speed that came was in place just about the time it was necessary to get back on the brakes to setup for the next corner. The corner was always met with the front end diving and then aiming for the outside of the corner (understeer). Front brakes (SRT-6) were definitely tasked out. Rears felt OK, but never even approached lockup, so more could probably happen there, too. Despite all of that, the feeling of what capabilities are on tap, the sound, the smoothness, the whole package. Words cannot describe it all. If you have ever ridden in a E/S/CL/whatever-55 AMG, you understand the feeling. Now put that into something more than 1000# lighter, mix them together, now you've got a slightly better idea of what you're dealing with. Not everyone's cup of tea, but if that sounds even a little appealing to you, track me down at an event, we'll go for a ride!

I have a lot of experience with mountain driving, having lived in the Rockies for many years. The roads there are sometimes great, sometimes rough, but always challenging, no matter what you are driving. However, this car was all new to me, and it is a handful. To that end, a few adjustments are in order.

First and foremost, tires. The car is running decent tires (Continental rebrands) that were purchased when this car was only a N/A Limited. Time to step those up. I talked tires a long time with the 'faster' folks at the event, and most like Hankook for these cars. Most wanted a 235 tire up front, and a 285 in the rear. I currently have a 225 up front and a 255 in the rear.

Second, brakes. The spacers and lug stud conversion have shown up for the SLK55 brakes. These will be put on, but even they will be a stop gap until a set of 360mm/6-pot brakes can be sourced. Probably should consider the 4-pot rear brakes, if a set can be found.

Third, springs. Currently, there are SRT-6 springs on the front of the car. With the N/A engine, the front end sat sky high. With this engine, it sits like it is an SRT-6 on lowering spring. They're too soft for this setup, and probably the primary contributor to the understeer and extreme dive in the corners. In any case, with corner weight data in hand, consultation with some spring manufacturers for slightly stiffer springs is in order. The next concern will be that the Bilstein B6 front shocks are going to have issues. Not looking for race suspension and the associated harsh ride, so will need to think about B8's or something equivalent to give a good mix of handling and comfort. Stress on that second part - this is still my Wife's (Donna) car. She doesn't want a race car ride, either.

Fourth, LSD. Not that kind. This winter work must commence on the HAG215 project, and the Wavetrac limited slip differential. It looks like the code has been cracked on how to get that larger differential in there, but no one will know for sure, until it is done.

Fifth, exhaust. The only other problem that crept up on this trip was an exhaust leak that needs to be tracked down and killed with extreme prejudice. Nothing like making your hard work sound like a jalopy!

Some parting notes.

The SLK55 seats kept you absolutely planted. No sliding around, excellent support, and very comfortable. Driving position for my 5'8" frame was perfect. My 17 year-old, 6'3" son drove the Tail of the Dragon in this car (Yeah, I deserve a medal for that one!), and he could not fit in the seats properly for this type of driving. They sit a little taller than the Crossfire seats, and he had visibility problems, especially with right hand ascending turns. If you're an average size person like me, you'll love them. If you are already having trouble fitting in a Crossfire/SLK(R170) then you will hate them.

I have built more hot rods in my time than I can count. While high strung four cylinder turbocharged engines are my passion, I have had more than my fair share of hot V8s. I have never experienced an engine like the M113K. This particular one was a virtually unknown engine, with only assurances from the seller that "it ran fine when pulled". What is known is that it sat out of the car for over a year, under a tarp in the hot, humid air of central Georgia. The only work done to the basic engine is the work that you see in this thread (fluids, gaskets, water pump, etc). Most of that was normal, preventative work. The engine never got hot, did not burn a drop of oil, and the oil now looks just about as clean as when it went into the engine 800 miles before this thrash of a trip. No one could ask for anything more from it.

My original intention was to end this thread, right about here. The driveline is in the car, runs and drives well, and looks complete.

However, after thinking about it, there is more to add to this thread. The swap is not complete until the entire package of what it takes to put a M113K into a Crossfire/R170 and take this back to a well balanced, sorted car is complete. Sure, it's fast. It's comfortable, the project could end right here. However, this swap should perform as if the car had come from AMG. Power-wise, it does. Handling still leaves some to be desired. Long term durability of the rear end is in doubt. Until these items are fully addressed, I do not consider this a completed project.

In the meantime, I'd like to thank everyone who has read along on this journey. It may seem like it just started to the casual observer, but it required hundreds of hours of work, long nights, and little sleep in a few places. There was general anxiety about many things, including the aforementioned junkyard engine, electronics, cooling system, fuel leaks, incompatible parts, and so many other details. I am hoping someone out there will read all of this, feel inspired and empowered to make their own M113/M113K swap a reality. I'd also like to thank the many people who offered advice and experience, both in the thread and via PM's. You know who you are.

I'd like to thank my son, William, for all his help along the way. Most of all, Donna, who declined issuing a missing persons report, or just finding a replacement husband. I'm coming in from the shop, now, Dear.