i have a 1983 trans am 305 engine 5.0 litre v8 its starting to develop tapping noise me and a friend think tappets, but when i took it to another friend of mine he says the tappets are auto adjusting (oil)? he doesnt do a lot of work on american cars so i wanna check before i have someone else to look or could i do this myself with a feeler guage?

ONE MORE QUESTION - i live in the UK and was wondering why such a car with this engine has a speedo that only goes to 80mph, whats the speed limit in the good old USA?

PROLONG ANY GOOD??

 

"Tappet" is just another word for "lifter".

Try adjusting the rockers. As things in the valve train wear, tolerances change; and although the lifter is self-adjusting over a certain range, the tolerance can exceed that range. When that happens, they tick.

You can do it yourself. No feeler gauge required. With the engine running, back off each rocker nut slowly, one at a time, until it ticks; then tighten it slowly until it just stops ticking. After doing all 16, shut off the engine, and tighten each nut an additional ½ turn. That's all it takes on this kind of car.

The speed limit AT THAT TIME was 55 mph everywhere in the US. It was illegal to manufacture a speedometer for a street car that could indicate above 85 mph. It has since been raised back to where it used to be; it's now anywhere from 60 to 75 in most places around the country. Each state and county and city sets its own, it's not a nationwide thing like in some countries. But it was for a few years.