New Truck - Problems - help

[jlolson]

Hello All,

I'm new to this board and have been working on my new '71 LB C20 w/5.7L 350 for about several weeks now. There's a couple of problems I haven't been able to nail so I thought I'd ask here:

1) The spark wires and rubber caps near the exhaust manifold were melted but functional when I bought the truck. I just bought a new set of Duralast plug wires today and after a 10 minute drive I smelled the burning rubber. They are melting again. Do I need to buy better wires or am I getting super hot headers for some reason?

2) The truck has a new carb and I've spent quite a bit of time dialing in the idle speed, idle fuel mixture, and timing. It's an automatic 350 and idles in drive with the AC on at 550RPM and the timing is set perfectly according to the service manual. It still diesels badly when I shut it down. What else can I do?

Thanks,
Jarrod