*Professlonal lnstallatlon Is recommended*
Small Block Chevy screen trays only use three studs: two In the #2 main cap, one In the #4 main cap opposite the dipstick side. The rear hole mounts to the all pump mounting stud/bolt. Big Block Chevy trays mount to #2 and #4 mains, and to the all pump mounting stud/bolt. Eonl trays use both studs in the #2 and #4 main caps.
Note: All main caps are numbered from front to rear, #1 - #5.
When main caps are removed, use a tap and/or thread chaser to clean all thread sealer/thread lock from the threads. Install main studs in block with either a stud Installer, or simply double nut the stud and tighten. Reinstall main caps, and finger tighten the nuts. Do Not Torque. Test fit tray and pan. Look for any interference due to stud length and/or Improper tray height. Remove tray, main caps and studs. Reinstall main studs using thread sealer/thread lock.
Reinstall main caps. Use a large washer between main cap and nut. Torque.
SBC & 302: ( Part #'s 20-920, 20-921, 20-940, 20-941) 30 wt. all, -82 Ibs. Moly -65 Ibs.
BBC, 351W/C, 302R: (Part #'s 20-926, 20-942 " 943) 30 wt. oil, -125 lbs. Moly 100 lbs.
Install tray, using nuts provided. Torque to 20-25 lbs. Thread lock is recommended. Manually turn over engine, checking for interference with rods and counterweights. Reinstall oil pan.
If the main studs hit the oil pan, it is best to remove material (cut to length) off bottom of the stud (block side) one thread at a time. If the tray doesn't fit in the pan, recheck the part numbers. If correct, try and find where the interference is, correcting by slightly bending and/or filing. Make sure all thread sealer from the main cap holes and/or metal chips from the main studs are cleaned from the engine before you install the oil pan.