Lead substitute

[HectorHeadgear]

Does anyone know where a reliable source of lead substitute is? I haven't rebuilt my heads yet, and it's been hard to find a reliable source. None of the parts stores around me have it. Sometimes I get lucky and find it at a Chevron or something.

Also, on a different subject, what's the theory behind chosing an oil weight? I'm at sea level in a mild climate. (coastal socal.) Does using too thick an oil cause oiling problems at all? What are the benfits of using a thicker or thinner oil? I'd appreciate some input on that. I have a '73 360 with nearly 200k on it. It's had some major work, but never a complete overhaul.

[J4GRAND]

I was told by the guy who did the head/block work when I rebuilt the 360 in my J4000 that the AMC motors didn't need lead additive as they used hardened valve seats long before unleaded gas came into widespread use.

As for the oil, thicker oil works better in a warm climate and in an engine with high miles like yours has. The only problem with using too thick an oil can be drainback problems if the engine is full of sludge. Too much oil remains in the top end and not enough is being pumped to the main and connecting rod bearings. However, I wouldn't see a problem with you using a 20w50 oil in your Wag.

[HectorHeadgear]

Thanks. That's kinda what I figured. I am running 20w50 now. I usually do the lead substitute every 2nd tank 'cause the factory manual indicates leaded gas. But a guy who's rebuilt many 360 heads would know what damaged 'em and what didn't, so I'll make it less of a priority. Once I get my heads rebuilt, I won't have to worry at all. (Don't know when that's happening though! Hopefully this summer.)