I purchased a 1971 240Z in 1979 for $1,000.00. It was Safari Gold and had been hit in the Drivers front. The car had a 4 speed and air conditioning and ran very good. My body guy repaired the damage and repainted the car with Dupont Imron paint. Shortly afterwards I loaned the car to a friend who preceeded to overheat it and blow the head gasket warping the cylinder head. I tore the engine down and brought the head to our local machine shop. This was in a small Arizona town population 7,500. I picked up the head and it looked quite different. The combustion chambers were no longer round, the machinist had milled 60 thousanths off the head. I began to install the head and noticed the abnormal amount of slack in the timing chain. I did not have a lot of OHC experience so it was off to the dealer to find a solution. The service manager said way too much meat was taken off the head to shim the cam towers. Not having the money to buy a new E31 head, I opted for 3 sets of cam tower shims. I was informed if I used that many shims there would be no way to get the camshaft true and I would be wearing out cam bearings and breaking camshafts. I took the shims home and bolted it all together. The timing chain slack was gone and I could turn the engine without the valves contacting pistons. I decided that since I was into it that far I would install a set of exhaust headers and a new 1 3/4" Exhaust with a single turbo muffler. I ran a compression test prior to start up and had 215 pounds on all 6 cylinders. After taking the car out for a test drive I was very surprised at the increase in performance. This little Z was crazy fast. The midnight drag races out on Thornton Road was kind of a thing to do, so I decided to give it a go. The Z was dominating everyone, 55 Chevy’s with dual Quads, Mustang’s with 351 Clevlands, Chevy Camaros, I was not only winning but by several car lengths and going through the 1/4 mile still in 3rd gear. Being curious as to what kind of time I was running we decided to go to the Local Dragstrip for the Friday night grudge races. I ran 3 passes in the econo class, besting a Mazda RX7, a Ford Capri, and another 240Z with triple weber carbs. My best time of the night was 13.9 @ 101.3 mph. I kept that Z for 14 years and racked up another 140,000 miles without any issues whatsoever. Finding fuel was a trick, I found a 50/50 mix of Leaded Regular and 93 Unleaded Premium would keep the engine happy. It was totally an accident this Z became so fast. I was 19 years old, I took auto shop in High School. I wasn’t trying to build a racecar, just trying to put it back together. If anyone out there has HLS3040204 I would like to talk to you.