I have a '77 F-250 4x4 with a 400, Edelbrock 4 barrel intake, Edelbrok 1406 carb, long tube headers, Performance distributors D.U.I. distributor, Auto trans with 4.10 gears. Melling MTF-2 cam. Everything else is stock.
Heres the question:

11,000 miles on the motor and developed lifter tap on the #4 piston exhaust port. Pulled the lifter and it is cupped so I need a new cam. More than likely its my fault for breaking the motor in w/ Mobile 1 synthetic which I found out later is not such a great Idea. I need advice on a replacement cam.
The old one did not seem to have much low end torque at all. With a different cam will I need different length push rods?

Old Cam Specs:

Cam Lift int. .281 / ext. .296
Valve lift .486 / .512

sae duration 282 / 292

.50 duration 204 / 214

Thanks for any advice.

 

Moved to proper forum for help with the 400.

 

Can't help much on the question BUT, just wanted to say your set up is exactly like mine. Wish I had 4:10's so it would move from a stop a little quicker.

I have a melling cam with the edlebrock RV cam grind (what PO told me), and I like it.

Off topic, I LOVE the DUI dizzy. Pics in my gallery.