I have a 72S Targa that is in A+ Driver condition -- with recent refurbished interior and rebuilt engine to original specs. I am planning to replace my heat exchangers and muffler and would like opinions. I have heard arguments both ways on the exchangers: standard Dansk (?) reproductions in cold steel vs. SSI stainless steel. (My plan is to drive the car no more than 4-5000 miles per year in no-rain, no-snow weather, an perhaps show the car in local/regional PCA events.) Should I save a few hundred dollars ( and stay more "original") with standard steel boxes, or invest for the longevity of stainless?

Also, I have read where some enthusiasts use "jet hot coating" on new heat exchangers and mufflers. What is that and are there advantages/disadvantages?

Thank You.