I'm thinking on trying a set of "shorty's" as ive tried a few sets of full lengths and they come in contact w/the torsion bars.I'm running the hi-po manifolds on the 340 monaco and these are great,as i even ported and hogged out these manifolds.I've seen some tests against full length headers and these hold their own.Past 6000 rpm they drop like a rock.I swapped the headers for the manifolds at the track on my Duster and still ran a 12.6 ,only 2/10ths off.If you find a set let me know i would be interested,i'm sure i could get at least 20 bucks for my 69 hi-po's.Glen