If HEI, pull dist cap off pull rotor, turn it over and see if there is a a black burn mark on bottom if there is the rotor is bad.
Also if carburated the carb could be going bad and backfire can be caused by lean burn , ( not enough fuel)
could be sticky valve, or wrong valve clearance, broken valve spring
You might also lubricate the centrifugal advance counter weight pins, use a small amount of white lubricate on the pins, make sure that the pins are not worn, check for sticking.
backfiring is a sympton of a lean condition. look for vacuum leaks and fuel delivery problems.
The valve timing is offAnswersounds like a possible worn camshaft lobe. a fairly common problem on late 70's Chevy small blocks
Rpm needs to be set at 800 - 900 .. that is factory setting.
I belive it is 4 degrees advanced at 500 rpm
an idle rpm for a 350 stadard trans. is about 500 rpms. an auto is about 750 rpms. this is if the eng. has a stock cam. if not it may vary
Standard transmision, 750 rpm. Automatic transmission, 600 rpm in drive.
The Chevy 350 is a V8 5.7 L engines which yields the horsepower of 200 @ 4000 RPM and torque is 310 ft/lbs @ 2400 RPM. It has designed by General Motors and started manufactured by 1968 until now with enhancing its power time to time. To know more about Chevy 350 and its complete description you can go through www.hiperformer.com/chevy350/overview.html. I refer this page for gaining information for my Chevy 350
1500 at first until it kicks down to 850 rpm
Need to know the year of the engine and if it is stock.
The practical limit is 6500 rpm. Above that and you risk parts failure.
A stock 350 cubic inch engine in a 1994 Chevy 4 x 4 will put out 310 foot pounds of torque. It does this at 2400 rpm.
With a 4-barrel carb. 155hp @ 4000 rpm
With a 2- barrel carb.- 165 hp @ 4000 rpm With a 4-barrel carb- 255 hp @ 5600 rpm
You should have about 10 PSI per 1000 RPM; a touch higher at low RPM and a tough lower at high RPM. If you car idles at around 800 RPM, 10-15 PSI is good. The 250 - 275 value mentioned by another poster would likely blow oil past all of your seals if it were possible ot get oil preasure that high.
For 1973, the idle speed for an automatic transmission is 600 rpm when choked, and 450 when warm. For a manual transmission, 900 rpm when choked, 450 when warm.
It is best to start at 8 degrees at 600 rpm for auto and 6 degrees at 800 rpm for manual. The total timing should be around 33 degrees.
160 hp @ 4400 rpm
Any V8 engine, operating at 1,000 RPM, fires 4,000 times in a minute. If operating at 2,000 RPM, it fires 8,000 times in a minute.
4 BEFORE (ADVANCED) TDC A 800 RPM WITH THE VACUME ADVANCE DISCONNECTED AND PLUGGED.