Type of gas

[Larry]

There was a big scare (mostly phony) a few years ago when the lead was eliminated from the fuels. All the brainiacks were screaming about "valve seat regression" with the lead "cushion" gone. People were running around with their hair on fire, pulling their cylinder heads off and paying huge machine shop bills to have hardened valve seats installed. A total waste of money.

It was later proven after lots of tests that if you had something like an early Bonneville station wagon, fully loaded, pulling a trailer up mountains, for 50,000 miles, you "might" find some valve seat regression.

The scare is pretty much over, although you'll find some very high performance engines still getting the hardened seats.

Your 2-bbl. 350 will be happy as a pig in you-know-what on the lowest octane fuel (remember, the octane never had anything to do with lead either). If you get any pinging under anything but severe loads, just move up a fuel grade or retard your timing a bit. A small amount of ping doesn't hurt.

Now go out, gas up your Pontiac, and enjoy!

[Larry]

Most gas stations offer 87-89-91 (I think). I have run the 87 in all my newer cars, and "treat" my 400 engine '40 Pontiac to the 89 most the time. However, that engine is '74 Trans Am and thus the lower compression, so 87 would probably be fine too.

Because your '71 is before the compression drops, you might need to experiment with gas. Try the 89 and see if it doesn't ping (and that your timing is correct). If it "rattles" a lot, you may want to retard the timing (which will lose some of its pep!), or go to the 91.