Funky, use this chart. Use Gr 5. We don't ever need gr 8 on an old truck. You are probably talking 1/4 or 5/16. Anyway, for future, measure the OD of bolt threads, calculate or measure pitch. (fine or coarse) and use the chart. This is a small bolt, it is performing a gasket clamping function in this case. Not holding a bracket, etc. No high torque here. Just snug and a tiny more. Keep hand near where wrench handle meets socket so you can't get much handle leverage. Other cases with small bolts and non gasket, snug plus slow turn to "tight". Torque wrench can be used. As bolt size gets bigger 3/8 7/16 1/2.. use clicker torque wrench. Normally a person can tell by feel that you are getting into the elastic stage....that's a no no. I hardly ever use a torque wrench except on a critical big thread size.. .
Lug nuts, head bolts, pinion nut, axle, steering stuff. You just get a feel after awhile.
CLICK
The charts do not contemplate a gasket/sealer scenario. Read sealer instructions if used. You are only sealing an oil leak, and mechanical support against cam lever load, not fuel pressure.
No big deal. BUT!!! 1/4-20 are the most dangerous bolts we use. Head will snap off. Oil pans and diff covers are in this gasket/small bolt/oil leak category. Water pump needs caution also. Fastener work/restoration needs calipers, thread gauge, taps and dies and torque wrench.
SBC specs say 8-11 Ft Lbs for fuel pump. Cast iron thread and gr 5 bolt.