Critical Items During Rebuild

Items to be checked prior to assembly:

1) Check all castings for rust and scale removal.

2) If a steel 1/4" pipe plug (usually allen-headed) has been installed in the center of the rear wall of the valve chamber, remove it and replace it with a brass or stainless plug.

3) Check the floor of the cooling water jacket in late model heads, directly below the thermostat housing opening for the presence of a small pin hole (in a location that is just slightly under the edge of the head gasket). These holes can be repaired by drilling and tapping for a 1/8" pipe plug.

4) Inspect the lower 1" to 2" of each cylinder bore, especially along the cam shaft and water jacket sides, for any discoloration that would indicate extreme thinness and possible pin hole leaks. Probe any discoloration with an ice pick.

5) Check for maximum gap of .005" (total) between head to block, and manifold to block mating surfaces.

6) Oil passage ways in block thoroughly cleaned.

7) Oil passage ways in crankshaft thoroughly cleaned.

8) Cam bearings installed with oil holes aligned with holes in block.

9) Inspect threads within stud holes in block and dry-run studs to check for fit. If any studs are quite lose, replace with a 10mm stud, or install a repair bushing.

10) Inspect inside of thermostat housing for proper configuration.

Items to be checked prior to installing oil pan:

1) Three oil plugs installed; one at each end of the cam shaft and one directly below the oil pressure regulating valve.

2) Timing marks on crankshaft and cam shaft gears aligned.

3) Two set screws installed to retain idler gear spindle.

4) Check max ring end-gap of .018" on at least 2 cylinder bores.

5) Check max of .004" between ring and ring grooves in pistons.

6) Pistons installed with number one toward flywheel.

7) Pistons installed with arrows pointing toward reversing gear, or with slots in piston skirts pointing away from cam shaft.

8) Rods installed with numbers pointing toward cam shaft.

9) Alignment tabs on rod bearings placed carefully in their respective recesses in rods and rod bearing caps.

10) Each rod checked for side play after installing rod bearings.

11) Oil strainer installed with proper slope along bottom of oil pan, and with some clearance so as to not press on the bottom of oil pan (spring between screen and 1/8" street el should be almost fully compressed).

Items to check before installing head:

1) Proper roughness on block deck and head mating surface. (Scribe lines using an ice pick or similar tool.)

2) Seal all studs into block using Lock Tite.

Items to be checked before installing the aft housing:

1) Make sure that the shifting lever shaft rotates freely within the aft housing.

2) Run feeler gauge under oil strainer to be sure that the screen is not pressing on bottom of oil pan (minimum of .005").

3) Install small pilot bearing in rear of crankshaft.

4) Check that idler gear is installed properly and that a cotter pin is installed in the castle nut on early model engines.

5) Clean oil collection groove and return holes in flywheel housing.

Finishing details:

1) All studs extending through head nuts the same distance.

2) Clean up all extra sealer.

3) Use standard length bolts on the following components:
Oil pan 5/16" x 7/8"
Rear oil seal housing 5/16" x 1"
Electric fuel pump bracket 5/16" x 3/4"
Accessory drive bolts 3/8" x 3 3/4"
Fuel pump 5/16" x 7/8"

4) Use copper or brass flat washers under water jacket side plate bolts, under the reversing gear cover plate, and under the lower three bolts in the rear oil seal housing.

5) Grind bottom of sheet metal flywheel cover flush with housing.

6) Trim the end of the upper left water jacket side plate stud (if installed) so that it clears distributor cap on late model engines.

7) Put a slight bow in late model valve cover plate so it presses in against the gasket on each end.