74_5.0L_Z

All 260Zs came with R180 differentials. The coupes have 3.36 to 1 gear ratios, and I think the 2+2 models had 3.70 to 1 gears. The 240/260 is easily upgraded to the R200. The easy way to identify an R180 versus an R200 is to look where the axle enters the differential. If the axle enters the side of the differential case through a bolt-on flange then it is an R180.

On pump gas with iron heads you are limited to about 9.5:1, if you go to an aluminum head you can run about 10.5:1. The higher your compression ratio, the higher the combustion chamber pressure will be. If the combustion chamber temperature reaches a critical temperature before the spark is introduced, you will get early combustion. A flame front will be started by compression then another initiated by spark. The colliding flame fronts cause knock, and huge pressure spikes. The result is broken engine parts. This is somewhat of an over-simplification. Your actual maximum compression is affected by the cam profile. If you run a cam with a lot of overlap, then you can use more static compression. For a motor that will live on the street I'd sick with the limits given earlier. Thanks, Dan

I like some of what I saw on the CobraZ site. Some other things I dislike. What I like: 1. I like the simplicity of their mounts. Mine are more complicated. What I dislike: 1. The engine is too far forward. About 2" further forward of mine. It looks like the reason for this was the factory shorty headers. 2. The engine is too high and at too much of an angle. Again I think this was too allow use of the factory headers. The datsun differential is mounted at approximately 5 degrees nose up, so the engine should be the same. From the photos on the site the angle looks greater. My engine is mounted at 2.5 degrees nose up, and the tail differential has been raised to match. The high mounting position of the CobraZ and the large angle will prevent use of the factory 5.0 clutch fan. 3. The CobraZ will need to run a remote oil filter. 4. The cobraZ will need a hood scoop, and/or a tiny air cleaner. 5. The T-5 shifter will not be aligned with the shifter holes in the floor or console. One more thing Cobra engine have factory roller rockers; the engine shown on that site does not.

I have found an R200 LSD from a 1988 300ZX. It is the clutch type. I have some questions. Can I use the half-shafts from an earlier R200(That's what is in the car now)? It it as simple as popping out the 300Z half-shafts and popping in the 280Z half-shafts. Can I use the early style rear differential cover? I know that there is a special brace available that clears the finned cover, but I don't want to buy it immediately. What is the break-away torque of the 300ZX units? Thanks, Dan McGrath

My 1974 260Z with a stock 5.0L / T5 has run a 13.21 @ 103.6 mph on street tires. With drag radials, the car would easily be in the 12's.

I get the following codes: 67, 81, 82, 85 These codes are generated because I don't have the air pump solenoids (AM1, AM2), the canister purge, or the VSS connected. These are Key On Engine Off codes. I haven't been able to retrieve any Engine running codes. This might be because I don't have a clutch engine switch connected.

The speed sensor on the T-5 is used for two things. First, the computer uses it to determine whether you are idling at a light or coasting. The computer has different fuel, spark, and EGR modes for idling at rest or coasting. The other use is for cruise control. The tachometer should be triggered SPOUT connection coming from the distributor (the SPOUT connector is electically equivalent to the negative side of the coil). You can pick up the connection at the driver's side firewall connector.

Here are some numbers to put things in perspective. If you have 24.7 in tall tires (245/50/15), 3.545 gears, T-5 transmission. 6200 rpms in 5th gear is 189 mph. If I were you, I wouldn't worry too much about getting gears taller than 3.36 or about fitting tall tires. The limiting factor on your top speed will be horsepower and drag coefficient, not gear.

The speed for a given distance from the center of the rotor is given by s = R * w where w is the angular velocity of the wheel in radians, R is the radius from the center of the rotor, and s is the linear distance. Therefore the larger the rotor, the higher the relative speed between the rotor and pad.

I am using copper header gaskets on my 5.0L ford engine. Before I installed them I went through 3 sets of gasket in 2 months. I've had the copper gaskets in for nearly a year with no leaks and no problems. They have a raised crush area around the port. They are a liitle more expensive but can be reused.

This probably doesn't help you very much, but the Ford EEC-IV engine management system uses a relay (WAC Wide-Open Throttle AC Cutt-off) that kills the power to the compressor for 10 seconds during full throttle operation.

I don't mean to dampen the excitement about these kits, but you cannot use the 5.0 mustang shorties without puuting the engine too far forward. The T5 shifter will not come out of the factory shifter hole in the body or console. I tried. With the engine as for back (header flange against the fire wall, and engine as low as I dared) the shifter was too far forward. I ended up using block-hugger headers, and slid the engine 2 inches further back. The rubber mount on the tranny is 4" behind the factory transmission body mount.

I have the 3.545:1 ratio in my 5.0 / T5 powered Z. I really like this combination with 24.7 in tall rear tires. I had 3.7 gears in the car when I first put it on the road. I changed them after 2 weeks of driving. I would like to try 3.36 gears but R200s with that ratio are hard to find. Currently, 75 miles/Hr in fifth gear is 2700 rpms. The car is a pleasure to drive.

I have built several carbureted 302. My experience says don't over-carb. I was most happy with Holley 600 double-pumper. I later tried a 750 and a 700. The engine was much more crisp with the 600 DP. So, If it me, I'd go with a 600 or 650.

The reason that I chose to build a V8 zcar was the ease with which a high horsepower to weight ratio can be achieved. It is not necessary to build an engine that is on the verge of self-destruction in order to have a very fast car. I have a bone stock 5.0L mustang engine in my car. The car has been a daily driver for nearly a year, has seen ~ 40 passes on the drag strip. I intend to auto-X the car this weekend. Although the car is not as fast as some of the more modified cars on this site, my Z is faster than most vettes, WS6 Trans Ams, etc... The car gets ~20mpg, and I have had no reliabilty problems.

The Neapco part number of the adapter is 2-2-899-1

I just finished mounting 1985 maxima front rotors and Outlaw 2800 series (1.38" piston) calipers on the rear of mine. They work great. I had to have custom plates made to mount the caliper. Here is a break-down of the costs: calipers (2) * 125.00 = 250.00 Mike(scca) rotors (2) * 25.00 = 50.00 napa brackets (2) * 60.00 = 120.00 custom hoses, misc. 50.00 afco pads 1 set 60.00 Mike scca This may seem excessive but was well worth it. Before the mod, the rears were worthless. Now the rears are extremely effective.

I have converted my front brakes to Mike Gibson's(scca) stage II set-up (11.5" x .81" thick vented rotor and Outlaw 4-piston(1.75 in)calipers. I am in the process of upgrading the rear brakes as follows: 1985 maxima fron rotors 10.75" x 0.81" vented Outlaw 2800 series 4 piston calipers (1.38") Custom mounting bracket My questions are: 1. Can I use the master cylinder from a 1974 260Z (does the rear side move enough fluid)? 2. If I use the later 280ZX master cylinder, should I also use the later brake booster? I have a later booster(it's huge compared to the 260 unit. Will the 280ZX booster supply too much assist? Thanks, Dan

As I see it, you have a few options. 1. You can sell the engine and try to find another. 2. You can install the engine, work out the bugs(fuel delivery, electrical, etc..) and later rebuild it with different pistons and heads. Good Luck, Dan

The heads could definitely benefit from porting, especially on the exhaust side. That being said, I would remove the head before attempting this. There is no way that you can prevent particles from getting in the engine if you perform the porting with the heads installed. I am contemplating getting some aluminum heads for mine (1100.00) or having a guy I know at a local port and refurbish my stock heads. He has a great machine for porting that allows him to match the ports to each other. He says he'll do the whole jobs ,including new springs, for $300.00. These heads will outperform the high milage stock heads that I have, but will not perform like the Edelbrock or TFS aluminum heads. It all comes down to this, "How fast you can go is directly proportional to how much you spend." (and I'm poor) See Ya, Dan

I have been using the stock cluth and pressure plate with a hydraulic throw-out bearing. The clutch and pressure plate have given me no troubles. The car has been driven 70 miles / day for 9 months and has ~ 40 passes at the strip. The engine is nearly stock and I am using street tires(no slicks). I average high 1.8 to low 1.9 60' times. I have never had any trouble with clutch slippage. The weak link will be the transmission and not the clutch. Dan

I am using a harness from a 1993 5.0L mustang on my 1989 5.0L engine(the 1989 harness was damaged while trying to extract it from the twisted wreckage of the donor car). I have had no problems. The later harness is the same as the 1989 except for some of the relays. Dan

The factory gauges have a variable resistor (the dimmer switch) in their path to ground. If you didn't use the ground attachments from the factory gauges then the dimmer switch will not affect the gauges. Good Luck, Dan

I am using the same rims front and back 15x8 w/5 in backspacing. I have 245/50/15 on back and 225/50/15 on front. I have coil-overs on all four corners. (10 in 200# on back and 12 in 175# on front. The 245/50/15 will fit on the front( I wasn't sure when I ordered tires so I got 225s). I still have OEM rubber isolators above springs. This is not a problem on back but on the front I only have ~2 inches of shhock travel. I plan to get camber plates for the front. What it boils to is get 1? x 8 rims with a 5 to 5.5 in backspacing.

I have 245/50/15 Dunlop SP8000s mounted on Centerline 15x8 inch rims with a 5 inch backspacing. I am running the coil-overs. The tires barely fit within the stock rear wheelwells. I have less than 1/8" clearance on the inside between the weld-on spring perch and tire. If the spring perch was relocated above the tire (8 inch 350 lb/in springs) ,and wheels with 5.5 inches of backspacing were used then maybe the 255 might fit. Good Luck, Dan