clicking, crackling sound?

I have a problem in my car that has been around a while, I would just drive around it so It wouldn't make the sound. Now I want to get to the bottom of it. If I am at about 1500-2000 RPM and I floor the engine it makes this crackling sound until the revs build up to around 3k-4k+, then it goes away. If I floor it while cruising it will make this sound also. My 351w never made this sound. I am wondering if its just the 302 is so mushy down low its hard to push the car until it reaches higher rpms. The other issue, is this pre-ignition. The only reason I could think its this is I did raise the compression up half a point to 9.0:1 with a stock almost no overlap 302 truck cam. Any ideas, or do I need to give more info?
[addsig]

It sounds like pre-igntion. You need to check your total timing. Also, do you have Vac advance? some vac advance units can advance the timing as much as 24* degrees. If you do, disconnect and plug the vacumm source and try to get it to ping. If it does not, there is your problem. Good luck.

Tony

Better fuel sometimes works if it's only off a bit and you don't want to retard the timing.

I pulled some timing, put in premium, fixed the problem. Thanks for both of your help.[img]/phpBB/images/smiles/icon_cool.gif[/img]
[addsig]

Too bad. My next suggestion was to tell you the car was no good and sell it to me [img]/phpBB/images/smiles/icon_biggrin.gif[/img]

You have way too many cool vehicles for one person. [img]/phpBB/images/smiles/icon_eek.gif[/img] [img]/phpBB/images/smiles/icon_eek.gif[/img] [img]/phpBB/images/smiles/icon_eek.gif[/img]

Glad it worked out.

<font size=-1>[ This Message was edited by: Gordo on 9/1/05 12:06pm ]</font>