I wanted to use lead additive (not substitute) but it seems really hard to get in my area.
Its also illegal in my area.
There is a hardened valve upgrade set available (its from indy)
https://www.moparshop.com/Online-Shop/Motoren-Teile/16219/Upgrade-gehaertete-Ventilsitze
its just about 200 usd.
How much work would that upgrade be?
Would you have to remove the cylinder heads?
If so can you do this without removing the engine?
Is there anything you should pay attention to? Especially if i want to push the engine hard from time to time.
Car is a 69 charger rt with the 440cui engine.
I would like to give my perspective.
1.Way back when, in the 1960's when muscle cars were all the rage, Amoco service stations sold their very highest fuel, probably 100 octane with no lead. It was commonly known among us as "White Gas." We all used it in our cars and as teenagers and guys in their early 20's we pushed our cars to the limit and in some cases, beyond. I can't remember anyone needing a "valve job" on these muscle cars,as it was called in the day. However, even though leaded fuel was the predominant fuel, the average family 6-cylinder or mild V8 seemed to need a "valve job" before 100,000 miles. I worked in a service station and this was a common repair for cars 10+ years old. So I know that lead in the fuel is supposed to prevent valve recession, but I think you need to consider if you will be putting thousands, or even tens of thousands of miles/kilometers on your car before you sell it or curtail driving it as much.
2. in 1972 Chrysler hardened the valves of its 6-cylinder engines and in the owners manual, which I still have, and just looked at the other day, it says that the 6-cylinder cars can use unleaded fuel, the V8 engines could also run on unleaded fuel, however if the vehicle was subject to towing or predominately highway driving then leaded fuel should be used every fourth fill-up, so a mixture of 25% leaded fuel would be OK for a 440. Back in the day, the lead content was about 2.2 to 2.5 grams per gallon. So, the Chrysler engineering recommendation would be only about 0.5 to 0.7 grams per gallon, so it's not much lead and that is only if you tow or use it for mostly highway driving.
3. I wish I could put my hands on it but right now I can't, but there was an MIT study in the 1970's about the content of lead needed to protect engines, and they concluded that 0.1 gram per gallon would be enough. So we are not talking about a lot of lead at all to do the job. they also concluded that at the time, there was no sufficient lead substitute. Now chemical engineering since that time has advanced, but even then, companies were selling lead substitutes, and the conclusion was that they did not do the job.
4. As you say, lead in passenger car, on road cars is illegal. There's a very good health reason for that.
Anyway, that is my perspective. Good luck in your decision.
