block hugger headers or manifolds

the fact that your car was a slant 6 has nothing to do with your headers not fitting,,,what type of motor mounts are you using ?? are they old and saggging?? that changes things making them not fit,,,

the early A body guys have tons of header issues,,there is a guy that builds block hugger type headers that fit the early A bodys,,and im sure they will fit your 74,,and they are not over priced,,ask around they are called spit fires, there is usually a waiting period as this guy builds them several sets at a time from what i have read on this site,,

also,,you may ask around i think a set of dodge ram or dakota magnum exhaust manifolds would work on any A body,,i have not tried them but the look to me like they would fit,,they both dump out in the rear ,,ask around on this topic also,, just my 2 cents hope this helps