First thing I did was to get an engine. Sounds easy because it is. Maybe too
easy? Obviously, learn as much as you can about the engine's history. If you're sourcing a crate or remanufactured, or if you're planning to rebuild a core, it gets very straightforward. For every other source, do this one thing at a minimum before you buy: check the VIN for the donor vehicle. Don't have the VIN? Here's how to get it with just the engine:
1. The engine serial number is on the left valve cover sticker and probably starts with "TNXE..." If no sticker, the serial number is also stamped on an engine block flat on the lower right side near the oil filter mount.
2. There is also a partial VIN located on another flat on the left side just forward of the bellhousing mount behind the starter motor location. The partial VIN will look like "J*GH######" and you may need a wire brush and flashlight to be able to read the stampings.
3. Contact Mopar, tell them you're looking at purchasing a used hemi engine, ask them to send you the VIN for the given engine serial number and partial VIN.
4. Check the full VIN against the National Insurance Crime Bureau database: https://www.nicb.org/how-we-help/vincheck
5. Also check the VIN against Carfax for good measure and possibly some recorded maintenance history.
I learned all of the above the hard way. I purchased my engine from a fellow on ebay, but at the time I didn't know about engine serial numbers and VINs. After a couple of months, I found the partial VIN and ultimately discovered that my engine was stolen. I was lucky - everything worked out over a couple of months. I contacted the police, the original seller paid me back, and since I already had the engine at a shop for some repair work, I purchased the engine again from the rightful owner at the time (an insurance company - they also said that the rest of the vehicle was still missing, but a few weeks later said the shell was found with little else). I also requested and received a notarized bill of sale from the company. Is it hot in here? Naw it's just my engine.
OK that takes care of the most important engine stuff.
It's also good to try to get some sense of the engine's health beyond odometer reading and what kind of oil filter is on it now. Not sure what to add here, because I thought I was looking at a healthy engine. I was able to get a compression test done by the original seller and it came back fine. The vehicle had only about 10,000 miles and was a year old. In short, a couple of the exhaust ports were shiny with some oily residue. I also performed an engine leakdown test and found about 15% leakage past the rings in a few cylinders.
Took the engine to a shop and they said that four
of the piston oil seal rings weren't even touching the cylinder walls! I suspect that's also known as poor manufacturing, and may be a big reason as to why the LS tends to have a better reputation for reliability. The shop did a very light cylinder hone, replaced the rod and main bearings, and installed a new set of piston rings.
After getting the engine back from the shop, I decided to get rid of the MDS lifters and found another potential problem, this time with the pushrods and rockers. Six of my pushrods (and their corresponding rocker cups) were scratched, and all of the pushrods were short and not very straight. I ended up getting a new set of rocker assemblies (they don't sell individual rockers to my knowledge), and a set of Manton pushrods.