Hello all,I'm looking at buying a NOS set of headers at a really good price. They are the 3 into 2 and then into 1 design ( tri y) and appear to be well designed and built but,the only issue is the bends are the normal press type not the mandrel type. I know there is a small decrease in cross section of the bends but am just curious just how much difference it would make on a slant engine? I'm happy to go mandrel bend headers and pass on these ones if there is a noticeable difference,but I think any header is probably by far a superior flowing exhaust over a stock type. The buildup I'm working away at ( slowly) is a twin Weber setup,EDIS ignition,ported head,mild street cam (prob the RV 15 grind or similar) . I understand the Dutra duals are probably favoured by most due to longer life,but I've always had a great run with headers,probably due to milder climate over here. Thanks everyone,looking forward to your thoughts.