Reply to "Help selecting a solid roller - Please"

If I understand your explanation, drivability isn’t an issue for you. You just need some vacuum to operate the power brake booster. For the record, 70° overlap based on seated valve events (advertised duration) is the most overlap I’d use in any 351C 4V engine that fits that description (i.e. occasional street use, some usable vacuum) or even a road race engine that must accelerate out of tight corners.

For your “rough idling – adequate vacuum” application I’d use a single pattern cam employing a Comp Cams “high energy” solid roller lobe, in this case lobe number 1476. Have the camshaft ground with an intake lobe mathematic centerline of 107° ATDC and an exhaust lobe mathematic centerline of 117° BTDC. The lobe lift is 0.3666” and the lash at the valve is 0.020”. The specs end-up looking like this:

Advertised duration - 288°/288° (at 0.015” tappet lift)
Duration at 0.050 - 244°/244°
Net valve lift – 0.614”/0.614” (1.73 rocker ratio & 0.020” valve lash)
LSA - 112°
Overlap based on advertised duration - 64°
Overlap based on “effective” duration at 0.050 - 12°

“Seated” valve events based on advertised duration:
EVO - 81° BBDC
IVO - 37° BTDC
EVC - 27° ATDC
IVC - 71° ABDC

The "duration at 0.050" of all solid tappet cams is over-stated due to the lash adjustment. To compare this camshaft to a hydraulic camshaft you can estimate that this cam’s “effective” duration at 0.050” will be in the ball park of 236° and therefore its “effective” lobe intensity shall be in the ball park of 52°.

Modern mechanical roller tappets seem to be the most troublesome application for the 351C lubrication system. Denny Wydendorf will tell you all mechanical roller tappet applications “must” use tappet bore bushings. However, for the record, and for the benefit of others reading this post, the Lunati mechanical roller tappets (72413-16 or 72459-16) have a reputation for metering oil properly if the block is not equipped with tappet bore bushings.

Since your Pantera’s engine IS equipped with tappet bore bushings you can use Isky’s tappet part number 3972-RHEZ. The roller of that Isky tappet rolls on a bushing rather than needle bearings, and the bushing is lubricated by "force-fed" oil rather than relying upon oil splash, thus resolving the two biggest failure modes of mechanical roller tappets, including street applications.