Mopar Action On-line – Tech Questions
Paul Mc Gough, Bakersfield, CA, 1973 Plymouth Duster 318
I got a question on exhaust. Right now I have astock ’73 318 duster and have a set of hooker headers (5901 HKR) and 2-1/2″pipes with Flowmasters. I’m building a 360 with 340 J heads. My issue is theheaders on the driver side hang down low and has already flatened two tubes.I have been thinking of going with the hedman short headers (hed-78500) andan X pipe to replace the speedbump finders. Do you think I will lose a lotof power with this set up? Thanks, Paul Mc.
It depends! If the engine will basically stock, not a cammed-up,single-plane high-rev deal, then the loss, if any, will be small. However,once the HP gets north of 400 or so, the engine — if you look at the dynocurve — will begin to “nose over” (lose HP) too early in the RPM range, soyou’d be killing HP and not even picking up any mid-range.