July Update
Swapped out the power steering for manual box. With the manual box there is some steering effort, but actually it is not bad at all. Car drives much better at highway speeds, no touchy feeling now. The power steering box with pump, hoses, and fluid weighed 57 pounds; the manual box weighed in at 19 lb for a 38 lb weight savings off the nose of the car. Had to buy a new pitman arm for the manual box. Even though the manual box was out of a 73 Duster it still had the small diameter pitman shaft; whereas the 74 Challenger power steering had the large diameter pitman shaft.
Replaced the 2.66 first gear in the 4 speed with a 3.09 first gear. Had to install a complete set of gears. Brewers Performance had a real nice used set, almost like new. All the other gear ratios are about the same. The larger step from first to second is not even noticeable, the engine is still easily in the cam’s torque range. When starting from a standing start don’t have to over rev the engine or slip the clutch a bunch. So the 3.09 first gear works real well with the 3.23 rear axle gear ratio.
Got tired of the oil light coming on sometimes when the engine lugged down while starting from a standstill with the old 2.66 first gear. I noticed when I installed the cam it just fell in the cam bearings. I prefer a tighter fit with some resistance, so maybe there is too much cam to bearing clearance even with new cam and bearings. So installed a high volume std pressure Melling oil pump, and a Milodon 8 quart oil pan. The pan hangs down about ¼ inch below the K-frame skid plate, so I added a skid plate to the new oil pan. The stock pan was about .06 material thickness, so I used about .1 (12 gage) for the skid plate. First welded a double thickness of washers to the pan, then welded the skid plate to the washers. This was done for the skid plate to clear the stiffening ribs in the bottom of the oil pan. I’m running 6 quarts total in the 8 qt pan. The oil level is about even with the slosh baffles at the top of the sump in the pan, rather than much higher/closer to the crankshaft as in a std pan.
Have just over 600 miles on the car. The .92 torsion bars are not too stiff, even with all the weight removed from the front of the car. The wife said the ride is good. The 1.125 front sway bar easily keeps the car level on corners. The two pairs of mufflers are quiet at highway speeds, but let you know it’s there when accelerating. The XV Motorsport seatbelts are easy to use and work great.
I may try a Lunati voodoo VH32 single pattern cam with 1.6 rocker arm ratio. Specs with 1.6 rocker ratio are 262 seat duration, 222 dur @ .05 lift, .499 valve lift. This cam has a little faster ramp rates and a little higher lift than the H215 cam that’s in the engine now. Would be a 3 degree step up in .05 duration, so won’t raise the power band too much. The VH32 cam is able to run with 1.72 rocker arm ratio, so the magnum head 1.6 ratio should easily work with it. I will say the H215 cam works great, torque comes on early and peaks about 5000 rpm.
Here is a photo of the new oil pan with skid plate.
