The torque specs for the valve tappet guide plate retainer bolts are 8-12 N - m, or 71-106 Lb-In, as per my Ford CD service manual.
When I replaced my lifters I just torqued mine to 15 foot lbs (12-15 ft lbs for valve cover), which now I realize turns out to be to much. The torque spec for the valve covers seemed comparable based on the size of the bolts and threads. The guide plate did not distort when I torqued it down so its probably just fine.
Is your head install complete?
94 Cobra, full Griggs, motor (overhaul in progress); 95 GT Conv, Explorer motor, Powerheads,TFS1,shorties,70mmTB,GT40intake,Quarter horse, CA emissions; 66 stock project car; 04 Silverado 4x4