Another Tach question

[57pickup]

Ive read the article on converting 4cyl tach for V8 use, it says 4 cyl tach will read 2x as much. Mine seems to read lower rpm I should probably get another tach and check it at 70mph it reads 1600 rpm. I realize with a 2 someting diff this may not be that far off . Anybody have any thoughts or ideas thx . Kirk

[Rickracer]

What kinda trans? If it's an OD, with a 2.xx gear, it may be right on the money,

[57pickup]

turbo 350