Reply to "UK GT5 Full engine rebuild - 351 Cleveland aiming for 400bhp"

Tom, standard 3-finger clutch covers have centrifugal weights that swing out at some rpm to add extra holding power. These do NOT fit a Pantera bellhousing and will rip out the internal reinforcing ribs (if not crack the whole bellhousing). Use ONLY 3 finger clutches without centrifugal weights, or have the weights ground off and the part rebalanced. Centerforce has a diaphragm pressure plate that works well & uses sliding, not swinging, weights. You may find that aftermarket clutches use a different bolt pattern or thread size than what your flywheel was drilled for. I didn't notice what flywheel you have, but the ring gear is separately replaceable on all. Redrilling and rethreading can be done by a competent machine shop. Or if the flywheel is stock, it can profitably be replaced from the clutch mfgr. Aftermarket flywheels are far stronger than stock & usually have multiple clutch bolt patterns.

Further back, I suggest a long-throw clutch slave cylinder. This is because heavy clutches or dual-disc types require more disengagement distance than the stock system can deliver. The distance can be checked with flat-blade feeler gauges thru the bellhousing inspection/vent port. A brand new Pantera with all-stock parts usually gave 0.040" of clearance between disc & flywheel. This is divided in two to get disengagement clearances on both sides of the disc: 0.020" is right on the ragged edge of acceptable. A dual disc cluch would need 2X that clearance to avoid drag of one or both discs. Using stock hydraulic parts often means the gear synchronizers in the ZF will drag a little with each shift.... and ZF balk-ring synchronizers are all-steel and will wear not just themselves but the mating gear-pair as well. A ZF overhaul runs around $8000 USD if most of the box is still useable. Some are over $11,000 USD... plus shipping.
All genuine ZF parts for these transaxles come from RBT Transmissions in the L.A area, as ZF sold the rights and all spares decades ago. ALL other parts are either NOT genuine or are recycled- used even though they may work OK.

Next, if you're going to re-use the cam you have, I hope you kept track of which lifter went to which position. Lifters and cam lobes mate during break-in, and this is a one-time thing. Swapping lifter positions has led to complete cam failure. If you replace the cam (Dan will have some suggestions), I suggest you include a new set of lifters & valve springs per the cam grinder's recommendations. The 351-C community has had far more early cam failures than is our fair share.
A couple of more oiling tips: replace the spring-pin found in most distributor drive gears; they will crack, stopping te engine most inconveniently. A split-pin with a second one inside, or an oversized pin from a 350 Chevy or other local engine, or even a piece of drill rod will upgrade this area. The next weak link is the oil pump driveshaft; stock ones are made of recycled coat-hangers and will twist in two on a high powered 351-C. Moroso, Milodon or Ford Racing sell a 4130- steel part for less than $20 USD. Cheap insurance. Good luck.