.035 is spark plug gap 30 degrees is the dwell setting
.035
The timing tab is on the left front of the block....It sets at 4 BTC 58-63...
The header manufacturers make a braket that straddles over the front header tube, and will allow you to mount it there. See your local speed shop.
Probably valve seals but also check the oil drain return holes at the back of the heads, they could be plugged up.
On the right (passenger) side of engine, just ahead of the front edge of the head there is a little flat area where the block extends a little further forward than the front edge of the head. The number is stamped on that flat area which is aprox 1.5 x .5 inches. You may need to sand the area a little with medium sandpaper, and then rub some white chalk on it. When you are finished, be sure to wipe some grease on it for rust protection or someday the number won't be readable at all, as the stamping is very light at best. There are many resources available such as manuals and the internet, where you can then look up the number. My guess is that you have the 283 which was common for that year, however there were a few other engines, both small and big block that were used on occasion. Good Luck Rick
.035
.35 of an inch
.033 to .038
That would be .035 in.
http://www.classiccarauto.com/impala/how_to/images/distributor.png
AC Delco 44 or R44 (R is for resistor) Autolite #86
A 1967 Chevy Impala with a 283 motor should run at a temperature between 180 and 195 degrees. The temperature is set by the thermostat which controls coolant flow.
The spark plugs on a 283 are wired the same as any other sbc.
the left rear underside of the engine
283 engine? approx 17 mpg
1 8 4 3 6 5 7 2
.035