Hi All, new to me 74 L-82. Runs ok, but thinking of changing the spark plugs. I have heard this can be difficult. One side is partially blocked by AC compressor.

Any advice ?

bill C

 

I have to get to some of my plugs from underneath the car, basically the same motor-1978 L48, all of the '70's small-blocks are the same dimensions and layout.

 

ok thanks.....how often would you consider changing L-82 plugs ? I had several originalmuscle cars back in the 60's and 70's and was changing plugs every 5,000 miles or so. Have been spoiled with new cars running 100k on plugs.

bill C

 

If the motor is running well and not drinking oil through the rings and valve guides you could theoretically go 20,000-25,000 on plugs, however we typically don't use our Vettes as normal highway cruisers so I wouldn't expect the same life from a plug. The L82 in '74 was only 9 to 1 compression ratio, it's not the same as the hot motors from the sixties and EARLY seventies, if your running everything stock I'd go 10,000 miles and read the plugs.

 

With the right set of extensions and u-joints, you can get them all from the top side. Might leave a little skin behind tho. They say on TV that blood and oil mix.
One reason we used to only get about 5K out of our plugs on the old muscle cars was the fact that the lead deposits fouled them up.
My 73 L82 says use R44TS plugs but since all my driving was around town, I had a lot better luck with R45TS plugs.

 

Personally, this is something that I do every spring. I pull plugs and check them, snug up the wires, clean contacts where I can reach them, clean the carb, change oil, filter, and fuel filter, lube everything that can and should be lubed, and go over all of the lightbulbs and other safety related stuff. I'd rather throw away a set of "half used" plugs than to be in the middle of a nice long cruising weekend and have to scrape knuckles in some hotel parking lot.

bill.