due to fuel now being 10% ethanol and soon to be 20%(Texas)is there any specific type that should be used.this is on a 1977 5.9L(360)engine in a dodge 1 ton van rv.
I don’t think ethanol in the gas would get to your valve stem seals, they’re used to keep oil out, not gasoline in. And why do you think TX gas will be going to 20% ethanol? Only recent talk is to permit gas stations to sell E15 to newer cars, but at separate pumps.
If E15 does become common, how many gas stations do you think will really have another tank put in the ground? I suspect that most would just switch to E15 only, just like most (if not all) of my local stations are E10 only.