Before & After

[Quigley]

I got my 401M ready to go and fired it up today. Used a donor 305E for the oil pan, filter housing, oil pump, and timing chain cover. New fuel pump, water pump, valve springs, timing chain & sprockets. 650 Edelbrock conversion, new gaskets and paint job. Going to put it in my 62 3/4 ton with a SM 319 overdrive transmission. https://youtu.be/bIMWFID3Zyk https://youtu.be/L93ftFdgodY Dave

[snazzypig]

Sounds great! Should be a fine engine for your 62.
What's the origin of the valve cover with the V6 in raised letters?

[snazzypig]

Meant to say valve covers.

[Quigley]

V6 valve covers were on the 401when I bought it. One was dented, so I used the GMC valve covers off the 305E donor. Dave

[snazzypig]

Just wondering when GMC used these valve covers with the raised V6?
Maybe on the later models?

[Quigley]

[QUOTE=snazzypig;70298]Just wondering when GMC used these valve covers with the raised V6?
Maybe on the later models?[/QUOTE. I'm not a historian on GMCs,I bet Bigblock would know. Dave

[Ed Snyder]

Originally Posted by snazzypig

Just wondering when GMC used these valve covers with the raised V6?
Maybe on the later models? I'm not a historian on GMCs, I bet Bigblock would know. Dave

I'm pretty sure they were used on the later models, perhaps in the bigger trucks after 1966. My 401 has them.

[BobBray]

I think the 'V6' valve covers came on 401's and 478's installed in Chevy H and J 70's starting in 1966. I have seen them on later V-6's installed in both Chevy and GMC trucks, including Toroflow diesels.

[snazzypig]

Now that makes sense. A generic V6 without the GMC stamping could be used in a Chevy or other non-GMC vehicle. GMC was also beginning to lose it's hard core identity by then.

[bigblockv6]

The "V6" stamped valve covers came out in 1972, it was corporate thing, roughly the same time Oldsmobile valve covers went blank on their Rocket V8 and no longer said Oldsmobile. Prior to 72 V6 engines used in larger GMC trucks just had blank value e co era with a sticker saying High Torque. With the "V6" stamped valve conversion 72it was one fits all that eliminated stamping two separate type of valve covers