Which gas is best?

So I have my '53 M38A1 with the original F134. It has 26,000 miles on it and I'm sure never rebuilt. I assume it was originally supposed to have leaded gas. What's the best fuel to run in it today? It seems to run on regular unleaded but I don't want to do any damage if I can avoid it by using something different. Higher or lower octane? Should I add "Instead O' Lead" additive? Were the military engines designed to run on "anything" or are they the same as the civilian engines?

Thanks!

Rob

 

I use the STP lead substitute in my '61 CJ5. Seems to do just fine. I was told that it is much better for the engine to use the lead substitute than just unleaded gas.

 

The only thing leaded fuel does for your engine is providing a slight lubricant to your valve train, even then it has more to do with the exhaust valve and seat than anything else.
You can use lead additive, or even have your cylinder head rebuilt with hardened exhaust seats and guides if you’re worried ‘bout it.
That be’n said, it’s highly debatable as to whether your engine really needs lead or not. There have been a few studies done and little to no difference in engine life has been found.
My Corveep runs an old leaded Corvette 327 and at first I was adamant ‘bout use’n lead additive but since read’n various reports on the internet have just kinda stopped worry’n so much ‘bout it.
Course for reference, I do plan to completely go through this motor in the future, at which time I’ll rebuild the cylinder heads and give it a full roller valve train, so I’m not really worried if I happen to wear the current valve train a little faster than normal.

 

i had a 65 chev that dad and i built as my first car, that had a 327 out of a vette in it, and i alwasy ran lead substitute in it. one day i just said screw it and 2 yrs later i sold it without a problem

 

With the number of miles I use the Jeep in a year I figure that it will take a long time before I might experience any abnormal wear on the engine. I have a can of lead additive to use but didn't see any improvement in engine operation by using it and can't see how it would help. With the price of gas today the addition of another expense is not worth it.

 

The ideal fix is to install hardened valve seats if you ever have the head off. Other than that it really takes alot of hard driving to be a problem. Running the lead substitute once every few tank fulls wouldn't hurt at all but you'll never drive it enough to really matter.

JB

 

Thanks everyone! You all seem to be saying the same thing so I'm not gonna lose any sleep over it and just run regular unleaded. I'm sure you'll be getting more questions from me soon!

Rob

 

Welcome from Utah! These guy's and gal's are the best for advice. They dont know crap when it comes to the winning powerball numbers.R)

 

I started out using an addititve, but for the last few years I just put in unleaded and wheel the pee out of the Fhead no problems so far.:hurrican: