IMHO...
The crucial factor for TTi headers(and other brands) to fit properly
is to be double sure that U have good motor mounts that are not sagging..
Just my $0.02...
Use the smallest size header that TTi offers for the '65 chassis and you should be okay. TTi stuff usually fits IF you follow the catalog suggestions correctly. You have to read all of the footnotes and you have to read everything twice.Thank you for the information and advice. The car has original K frame, mounts and steering. TTI offer a 1 -3/4 pipe, probably a better size for my engine build. I am aiming 450-500hp. TTI don't have a header to suit 65 with 1-7/8.
Thanks again