Hey y'all, still tunning my motor and haven't a clue what pinging sounds like (yeah I know this is like the billionith post on this, but nobody replies /forums/images/icons/frown.gif. The motor is a 355 using stock flat tops and 64cc vortec heads, about 9.5:1 compression. It has an aluminium intake and three core radiator. The distributor has the Mr. Gasket mechanical advance kit and I am using one light spring, and one medium springs, its kind of their generic reccomendation to use those. The advance can is 15 degrees and is hooked up to full manifold vacuum. The deal is that if I bring up to a mammoth hill and am moving pretty good, I'll have the SM465 in 1st or 2nd. I have the window down and while it's pullin the hill it kinda sounds like diesel when its cold, kinda of a steady knock. Its not a violent feeling or noise, just a noise blended in with the over top exhaust that I have. It doesn't do when I'm on the flat ground or flyin' up a medium hill. I have the initial timing at 8 degrees BTDC. Is that just normal lugging noise or what. Should I go over to ported vacuum? The springs all right? Should I use less vacuum advance? Thanks a bunch if you can help me. I was out tunning it and the gas gauge that said 1/4 tank was actually empty and I had to walk. What a day! ----------------------------------------- Where I last left off was I went out with my friend to take a fast moven ride in the new truck and turned out to be a medicore ebarassment. The poor little truck was running 210 with the heater and 235 without and made for one warm ride in 80 degree weather. I also left a giant size oil slick in front of his house when I got him. I floor borded it and bogged, hmm, wierd. Took it down to an old parking lot and was pulling cookies in the gravel and it died. I blamed it on timing and yanked off the #1 wire to hook the timing gun up. The crimp pulled off the wire, d'oh. It wouldn't start no matter what I did. We had to walk alllll the way back to his house to go get gas. Then I had to go back home to get a plug wire. I then limped home in it and began to here that noise. I tried to make a limiting plate for my vac advance and it ran worse with it, hmm. I then was lucky enough to find a BRAND NEW adjustable vacuum advance laying in a bucket of rusty parts outside my uncle's garage. It was someone's junk from years ago and that new advance was in it! I timed it up to 8 BTDC and put the advance at about half limit. It ran even worse?! Tons of dead spots and lugging at low RPMs. I backed it off some, and then a little more, a little better performance. I've got it back off quite a bit now and it runs a hell of alot better. It needed more advance because I was running 8 before to keep kicking at bay when starting. Everything is almost perfect. I'll take it in to have the quadra - jet professionally tuned and have everything check to make sure its kosher. While I was pouting about not having it running right, a pin hole leak in my rad tank started up again and began to spray everything. I was so ticked I took the rad down to be done and they did a marvelous job. They straighten the fittings, flushed it with some fancy chemicals and fixed that little hole. I also changed the fan clutch and it now runs around 190. The pan was leaking because somebody used the wrong seal under the timing cover when they put it on (I was off painting my damper). That one wasn't my fault and I happen to keep my left over gaskets and now that problem is solved because I installed the larger sized gasket. Thanks for the advice and especially about the temp having a large effect. I have no kicking at start and my lugging noise was due to a lack off advance. Once I get it reved the mechanical advance kicked it in and that why I had dead spots in a narrow low RPM range. I had it going with the timing light on and gave the throttle a tug and the timing jumped, so the mechanical advance is working A-OK. Now its gonna be terror on 4 wheels, hahaha.