2/3 crush leaving you 1/3 gap in a crushed ex pipe will not be doing you any favours; correct it asap.
For what it's worth. I've been using basic 91 octane in ALL my 12 cars from our 2001 T.Prado as recommended by TMC, down to my 1957 Holden FE, with 2 Falcon 351 V8's and many others, in between for the last 20 years at least. Always had full power and no issues, except for the fact that since we don't get LEAD anymore since 1986? I have noticed fuel tanks are more prone to rust, as some of you may have read re my need for a new tank for my 1978 XC Coupe 5.8 that I purchased Brand New. Even when we had the now obsolete SUPER (with lead), I always added UCL +-(Redex, Castrollo, SOO) in EVERY tankful, to lube the whole system, and still do.
As a kid, I took this advice from experts far more knowledgeable than me, and it must have been good advice as I still have all the cars I purchased since turning 16 to date, and NOT ONE has had ANY engine issues or damage, or the need for head removal, or special seats/valves fitted for ULP......................go figure.
IF WE
ALL FOLLOW PANDEMIC PREVENTION ADVICE TO THE LETTER, WE MIGHT ENJOY OUR NORMALITY AND OUR CARS AGAIN SOONER RATHER THAN LATER ?