lead addiitive necessary?

[mjwebb]

my 70 383 was just rebuilt, mildly...should I be running a lead addititive? thanks

[Ghoste]

If you can find it, sure but if you can't you are likely okay.  Did your mild rebuild include head work?  Did they put hardened inserts in the heads?  What heads are on there?

[histoy]

It's not necessary if you installed hardened exhaust valve seats.   My '64 had the old soft exhaust seats, so I used the CD2 additive for off road vehicles.  I bought it at Farm and Fleet. 

[mjwebb]

boy, was hoping for a yes/no answer :-)

I don't know the answer to any of those questions, just that it was very recently rebuilt...it runs super smooth and nice, definately feels and sounds like a stock engine, thanks

[ITSA426]

What heads are in it?  I put 452s on my son's car and they come with hardened seats.  Otherwise it's worth it to know if they've been installed.  Just be safe and run leaded racing gas.

[mjwebb]

everything was left original on the block, just the internal stuff was replaced