MGA Part Numbers - AEH647 -Bolt for Connecting Rod Cap, Twin Cam

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MGA Part Numbers - AEH647
Bolt for Connecting Rod Cap, Twin Cam - later production

PART NO.  SPL.PAGE  DESCRIPTION                                                                    
AEH435     TC.A.6    Bolt for cap (8) -(con-rod, engine, Twin Cam) -changed to AEH647-Com.(E)1343
AEH647     TC.A.6    Bolt for cap (8) -(con-rod, engine, Twin Cam) Com.(E)1343 -was AEH435

This is a special bolt for connecting rod caps in Twin Cam engines,
AEH435 - Early production - Fin.(E)1342,
AEH647 Later production - Com.(E)1343.
Notice the two precision pilot diameters.- with reduced diameter in between.

	AEH435 - Early production
	AEH647 Later production
The difference is subtle. The early bolt has a tapered nose. The later bolt is slightly longer with flat nose. In picture at right, the bolt on right is early production (taper nose), the bolt on left is later production (flat nose), the bolt in center is ARP high strength bolt.

The ARP bolt is good for the later style con-rods, but is a bit too long for the early style rods. To use the ARP bolt with early style rods, grind a taper on the thread nose, or use a hardened steel flat washer under the bolt head.

For additional information, see also Twin Cam tech article
TC-307D - Connesting Rods, Big End Bolts