| Diagram | Fig. 2 — CRANKCASES · ref 19 |
| Subsystem | engine bottom |
| Listed in parts books | 1969–1974, 1976–1980, 1983, 1985 |
Bolt, top front
Crankcase bolt, top front — 5/16 UNC x 2-1/2 in., used to hold the crankcase halves together.
This is a crankcase bolt that lives at the top front of the engine cases, holding the two crankcase halves together where the parts books list it under CRANKCASES and CRANKCASE - TIMING GEARS - OIL FILTERS. It's a plain fastener, but its job matters — it's one of the bolts clamping the bottom end of the motor together, so it needs to be in good shape and torqued correctly when you put the cases back together.
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The catalog shows this number appearing across a long production run, from 1969 into the mid 1980s, which tells you it stuck around through several updates to the bottom end without changing. It's a 5/16 UNC bolt, 2-1/2 inches long, in a hex head, so if you're checking what you pulled off the bench against a parts diagram, that's the one to match up.
If you're doing a full crankcase rebuild or just replacing tired hardware, it's worth having a few of these on hand rather than trying to reuse a bolt that's been in and out a few times too many.
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