Engine backfires

[Leggman]

I am running a 90 longbed with a 305 5 speed conversion. It has the stock TBI injection. It runs good but when I back off the gas it backfires like a cannon. My exhaust is what I scabbed up just to get me to the muffler shop. I know it leaks could this be the problem? Sucking cold air in I am told will make it backfire. Is this true? Thanks in advance for the help. Dave http://www.s10v8.com/images/smilies/icon_eek.gif

[ZR1BLAZER]

that is one problem for sure. best thing to do is get that fixed and then go from there.