1963 cj5 gas help

I heard i can't use normal unleaded fuel in my 4 banger is this true? Also if it is what will happen if i use normal gas

 

i use it in mine..??

 

you can use unleaded fuel in your f134. the problem is it does not have hardened valve seats, and a valve job wont last as long as it would running leaded fuel. the leaded fuel runs cooler due to the lead additive.

 

I have found a lead additive for fuel for "off road use only" that I use that seems to help the engine run quietier in the valve area.

 

thats all you need, the lead additive. when ever you take your head off for any work it would be a good idea to have harden seats put in. i had this done on my wifes 70 mustang. on the other hand ive never done it to my 350 sbc in my jeep and ive owned it for 20 years, and it has older 194 heads.

 

I really dont think its that big of a deal myself, I ran a SBC with the high compression 202 fulie heads for 15 years, with no ill results. granted it didnt like 87 octane fuel, but it would run off of it, and never burned a valve

 

The newer unleaded fuels have additives which negate the need for lead additives. When unleaded fuels first came out there were issues with exhaust valve and seat recession on high performance engines or engines that saw heavy loads. This was rectified years ago though. No need to put in an additive unless it makes you feel warm and fuzzy to do so. There have been many tests and studies showing that the newer unleaded fuels actually have fewer problems than the leaded fuels did. I had a couple around here a couple years ago but may have gotten rid of them when I cleaned out my office as I can't find them now.
I don't run additives in any of mine except occasionally some fuel dryer or some fuel system cleaner right before I plan on changing fuel filters. Have had no issues with any of my vehicles and I run everything hard.

 

Thanks nickmil. My boss asked me whether I needed to use an additive when fueling up my soon-to-arrive '66 CJ5. As a newbie, I found your explanation very helpful.