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dq409
08-31-2006, 12:08 PM
The guy down the street has had this engine sitting in the back of his 60`s truck for a while now.
All I could see while driving by was the valve covers that have the same W look as the 348-409`s.

I stopped by today and was going to look and see if it was a 348 - 409 truck engine but as I walked up the drive way I saw the GMC logo on the valve covers and knew it was the GMC six at that point.

Now,,, my question is,,, the six looks like a W block and was wondering if GM did the same thing back then as they did with the V6 of today as just loping off two cylinders to make that six from a 348?

Curious minds want to know,,,dq
JimKwiatkowski
08-31-2006, 12:32 PM
dq,here's some photo's of GMC V6


http://rides.webshots.com/photo/414765985/1414766987054402330ZMdHpN
IgnitionMan
08-31-2006, 12:32 PM
This is an early 1960's GMC truck 305 cu/in V6. This is a torque monster, not very powerful, unbelieveably heavy for a V6 (LOTS of cast iron), and fuel economy rivaled only by a 472/500 cu/in Cadillac V8. They were made in a couple of different cu/in sizes, but the most popular was his one, the 305.

GM also had a V12 for things like giant dump trucks, which was, in effect, two of these things linked crank to crank, front to back, and it weighed somewhere near 1,400 pounds.

Parts are expensive for them, from what I have heard.
SS425HP
08-31-2006, 01:16 PM
My Dad bought a 1963 GMC pick up with the V 6 in it. I used it to tow my 63 409, at times. It was a stump puller. Had monster torque, but wouldn't pass many gas stations. It was a 3 speed stick. Pulled the 63 like it wasn't there. Don't remember much about the internals of the engine. Don't remember having to do much to it. I do know that later on, in 64 when I was in the service, my brother drove it, and I think he told me he tore the tranny out 3 or 4 times! Not sure Dad knew about all of that. I know if I had done it, I wouldn't have told him.
GMC had a couple of engines they put back to back. They did that with a diesel, too. Knew a guy that had one. Made lots of noise, and was pretty powerful in its day. They were 2 strokes.
Look at the bore spacing in the photos Jim posted. And the Crank to cam distance. Huge engine. Like Ignition Man said, pretty heavy engine. You can see why. They must have been thinking about making that thing a lot bigger in the future.