Sorry if this has been discussed before, but I have a hard time doing a search here...

Is it necessary to have hardened valve seats on 906 heads ('69) while using unleaded fuel with limited mileage (1000-1500 miles per year). And, will a lead substitute/additive help?

Thanks!

having the seats replace with harden seat is just cheap insurance! lead additive is alway a good idea..

NORMAL lite driving ... it is OK. Lots of WOT or towing ...is a NO NO.

I wood not worry about it.

Worked at a Dodge dealer for several years, 72 thru 79, they are very good valve sets in there, don't worry about them, they will last a long time..

Big spring pressures and sustained high rpm will eat them up. If you aren't doing that all the time don't worry about it. A buddy of mine put 200,000 miles on a set of 906's with springs for a Crane SS305 cam.

Kevin

No, you wont have any problems. Drive your heart out..

Tanks guys!

My kids 62 300 had its OE heads till 2 years ago.He drove the h--l out of it for at least 9 years with no problems.Now it has my reworked 516s that were on my 440 for 10 years.Still no problems.Rocky

My old 440 combo had 906's that I did the valve job on. No harden seats and never a problem. Car ran 11.49 best with that mild 440 and I drove it from 2006 intil June 2011. Ron

Remember that the lead was a lubricant as far as the valves were concerned. Way back when the lead was being phased out, Don Garlits had a piece in the Detroit News. He suggested using an ounce of transmission fluid per ten gallons of gasoline to compensate. I use Marvel Mystery Oil per directions on the bottle. Absolutely no issues with valve seats over the years. Having said that however, it is important to be aware that the addition of any type of oil into the fuel system will lower the octane rating of the gasoline a bit.

Have over the years had a lot less problem with valve seats on Mopars than on the brand X's. seem that the cast is better on the Mopars and can take more. Drive it.

And don't waste money on the additives.
R.