I think you'll find that 350/130 with 190mm travel are Escort Cos front gravel
260/90 was early 3 door gravel
And that works very well as fast road car inserts combined with a spring between 275 to 325 lb/in.

When you see 425/160 or 500/200 you know you have tarmac...
The 160mm travel of the tarmac inserts is another hint...

It's no major problem fitting GpA inserts into standard road car shells..
There's two tops basically GpN and Group A:


The fat 20mm pin is the Group A..
All you need is some of those things on the lower left and a nice spherical bearing--


-Ford used an expensive 22mm ID high misalignment bearing, I use a 7/8" on (22mm is .866", 7/8" is .875) and some skinny spacers---I make them in stainless steel.


You can get rel nice copies in the UK for about twice what they cost over in USA

Remember, 2wd cars the strut bottom is 45.5mm, 4wd is 50,8mm.

This suspension stuff is how I mainly pay the mortgage.