The 11/16” tie rods were standard for some years police and taxi (but not all years). They are a bit stiffer but not much – but for daily use, they don’t wear out as fast as the 9/16” tie rods do (so I’m told).
As mentioned above, the big issue is the split adjusting sleeve. They deflect (a lot) under hard driving – and going with solid tie rod sleeves helps tons – for those who plan on hitting turns hard. Those split adjusting sleeves work good for about 90% of people, but those who drive hard - they are like soft rubber tie rods instead of steel.
This is a picture of a normal split tube adjusting sleeve
This is one example of a solid sleeve (there are others, as well).
Back in the day, if a person was driving a car over rough roads or potholes constantly, we would recommend replacing tie rods with 11/16” versions. That said, I don’t know of anyone today who would subject their FMJ to driving on rough roads or potholes, so a non-issue today.
Also, those who live in rust prong areas – the solid tubes keep things less rusty.
For those who are road racing or just drives car hard (ie: I fit that bill), the solid sleeves are well worth the money.
Sense I drive cars hard and plan on some road racing (with big blocks), the solid sleeves and 11/16” tie rods are the only way to go. The other 90-95% of our members, using 9/16” rods and split sleeves will be fine.
Side note: the 9/16” / 11/16” tie rods and adjusting sleeves are the same for most all Chrysler cars from early ‘60’s until ’89 – in both sizes (9/16” & 11/16”), which is surprising to me.
BudW