66’ 351E Engine Parts

[Aotte]

Have new to me 1966 V6 351E engine from C30, 51K miles. It is very original, however, it is locked up, will not rotate. PO reported it was last run about 3 years ago when removed from truck and stored in shed. Shed provided some protection in MI. Currently cylinders are soaking in Krol penetrating solution.

My question is what year along with engine size when applicable for: pistons, rings, bearings rod and mains, oil pump, gaskets, etc. are compatible with this 1966 351E engine? For example will 351 main bearings for 73-74 be comparable.

Thanks,
Les

[bigblockv6]

Head gaskets & pistons will have to be specific to all 305 engine from 1960-74, intake and exhaust manifold gasket are the same for all 351C, 379 as well as the non Magnum 401 and 478 engines manufactured up to 1965. Oil pumps are interchangeable with all GMC truck V6 engines regardless of cubic inches, same goes for rod & main bearings with the exception of 73-74 478M engines as these engines have considerably larger mains. The 351 was discontinued in 1972 and replaced with the 379 for 74-74, basically a 351 with the 478's stroke.

[Aotte]

Bigblockv6 thank you for the Information- big help.

To make sure I understand, repeating

For 1966 GMC V6 351E:
- pistons and head gaskets, specific to any 351 1960-74;
- intake and exhaust manifold gaskets, ( 1966 351E same as Magnum engine? intake same magnum or non magnum?? and exhaust magnum only)( suggestion mill flat do not need gasket)
- oil pump, are interchangeable with all GMC truck V6s, regardless of cubic inches
- rod and main bearings, interchangeable with all GMC truck V6s, with exception of 73-74 478M engine ( larger mains)
- timing chain, additional Q
- note 351 changed to 379 in 73-74, with 4.78 stroke, parts the same??

Thanks again,
Les



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[bigblockv6]

351 is from 1960-72, head gaskets from a 379 would be the same. Magnum intake and exhaust gaskets do not interchange with non Magnum gaskets as Magnum engines came with larger intake and exhaust ports. Magnum engines are the 351E, 351M, 401M, 432 and 478M, all these engines use the same intake manifold and exhaust manifold gaskets. The 379 uses the 478 crankshaft which has a stroke of 3.86 not 4.78 You can't use 379 pistons with the 351 because the piston pin height is different between 351 and 379. Timing chains were used on 305, 351 and 379 engines.