Set it with the timing light
I recently had to replace my water pump 1991 Toyota pickup v-6 3.0 3vze engine more than i bargained for!!!
everything was going smooth....until I moved my cam!!! woops what you have to do is make sure both cams are pointed at the marks/notches on the back timing cover...the left one might be pointed a little more to the left of the notch, and the right one may be pointed a little more to the right. the crankshaft has to be pointed at 0 degrees... the only way to be sure this is done proper is to turn the engine twice... use a socket attached to the crankshaft and turn it past the 0 degree mark once, until it comes back again (the second time) both marks on the cams need to match up exactly the way they started... next set a inductive timing light to number one cylinder, and gap the diagnostic terminal under the hood (use a paper clip and connect the e terminal to the te terminal (check manual for this, some years you must detach a vaccum tube!!!) after this start the truck, put the timing light on the crankshaft, and measure the timing... timing should be 10 degrees BEFORE top dead center (0 degrees) this is at idle (~700) if the engine is turning faster than this, the timing will be different.. best of luck and make sure the terminals are jumped!! otherwise the engine will try and compensate for the difference.
The timing marks on a Nissan ZD 30 diesel engine can be found on the front of the flywheel. The timing marks are scattered around the outside of the flywheel.
If the engine is stock, I'd set the initial timing at 12, make sure the timing mark starts to move when you rev the engine off idle, and watch it advance up to somewhere in the 30 - 35 degree range when it stops. Do this with the vacuum advance disconnected. Then with the timing set at 12 with the engine at idle, hook up the vacuum line to the distributor and see that the timing now shows somewhere in the high 20's to low 30's of timing.
if it is tbi you have to unplug the est, it is a single wire (tan/blk stripe) get a timing light and set the base timing at 0 degrees,then shut off the engine plug the est back in . unhook the neg batt terminal for 30 seconds to a minute , that will clear the codes, then put it back on and crank the engine , the timing should be set.
5w/30
two chains
Use Chiltons repair manual for the model year. Then you will find the engine specs. The points gap at 0.019 and the dwell will set at 30 The timing should set between 8 to 10 degrees before top dead center. Remember that changing the timing will change the dwell. Timing changes the dwell. but the dwell don't change the timing. So set the timing first.
5w-30
5w/30 from manufacturer
27-33 shoot for 30-31.
You will not really gain any H.P. It might make the engine perform better, but that depends what the timing is set at now. Ex: I have a 400 cu. in. Chevy small block, 450 h.p on the dyno, 400 foot lbs. torque. With say 89 octane the timing has to be set at 30 degrees, or the engine will run on when you shut it down. With say 94 octane or better, the timing can be set at max which is 36 degrees. The engine will be quicker and run much better, but in either case, I will still have 450 h.p.
5/30 weight synthetic
30 degrees dwell