GMC 702ci V12

[BigAL]

...but it's a friggin VEE TWELVE!!!!!!!!!!!!!!

And not only that it's a 702 cubic inch V12!!!!!!!!

[squirrel]

I think I'd rather have a 3000 hp Merlin......

If only you could afford one!

[Criscobath]

Only one place for a motor like that.

[BigAL]

So I'm thinking how hard would it be to put a couple of 6-71 blowers on this? Is there a way to run one blower off the back of the other blower?

[John Brewer]

Some of teh twin engine dragsters from teh 60's did what you were asking about. From the back bearing plate on teh front motor/blower to the regualr drive on the front of the back motor. Bayer and Freitas dual engine small block dragster comes to mind. Search web and see.

[squirrel]

two blowers is a neat idea. 4-71 blowers would work, too.

look up the "magnum" GMC V6 engines. They had better flowing ports, manifolds, etc.

[BigAL]

I like the idea of 4-71's would give it more of an old school look, you wouldn't happen to know the casting numbers of the heads your talking about, would you?

[squirrel]

no, but there's a GMC V6 group somewhere...yahoo maybe? those guys talk about this stuff. The Magnum parts came later on, in the mid 60s, I think.

[SuperBuickGuy]

that really is cute....

it really is a good thing Brian and Chad don't come in here.... they'd both have to take themselves to the hospital for a woody that lasts longer then 4 hours.

[oletrux4evr]

If only you could afford one!

You got that right........

[Deaf Bob]

no, but there's a GMC V6 group somewhere...yahoo maybe? those guys talk about this stuff. The Magnum parts came later on, in the mid 60s, I think.

One f the links I posted says which engines have the magnum heads..
Starting with the 351, not all 351's are magnums..
It also explains how to tell..

[Deaf Bob]

Magnum Engines

"Magnum" refers to 1966 and up 351M, 401M and 478M V6's with the large port heads.
The 351E V6 which was available from 1966 to 1968 in 1/2 to 1 ton trucks is essentially
a Magnum engine, as it has the big port heads and bigger manifolds. If you ever run
into some old magazine adds from 1966 it mentions the 351 Magnum engine available as
a high performance option. The 351's were available both as Magnums and small port
head 351C engines up to 1972. In 1973 the 351 was stroked to a 379, but never got the
Magnum heads and retained the anemic little WW2 carburetor. Though GMC never designated
the 432 with an "M" it was a Magnum engine. The intake manifold design was different on
the magnum engines to give more power and better torque by adding an internal baffle
that acts to develop better fuel distribution and also pulses that help to charge the
cylinders better. The exhaust manifolds have bigger and smoother passages and are
not restricted at the collector. They are found in 4000 and up series trucks. Magnum
Head V6's have much higher flowing exhaust manifolds due to the larger ports and passages
and the collector is considerably larger like about 3 inches in diameter. The 351E is in
all reality a pickup truck version of the 351M engine and has large ports and passages
in the manifold, but it has the bottleneck at the collector just like all the 305A, D
and E V6 manifolds. These manifolds are identified by their I-beam shape. 351M, 401M,
432 and 478M manifolds have even bigger passages but won't match up to smaller port heads
on the 305 V6 but will on the 351E which has the Magnum Heads. The 351C and 379 heads are
basically the same small port heads as the 305-A, B, D and E engines. 1960-65 401 and 478
also have small port heads but larger valves. 1966 to 1974 351E, 351M, 401M, 432 and 478M
share the larger port "Magnum" heads, that's what the "M" designation stands for. The bigger
"M" heads will bolt to a 305 if you're into increasing the performance of your engine.

[Deaf Bob]

It does not specify if the V-12 has magnum heads or not...
It is based off the 351... 351X2=702...
says above the 351 came with and withOUT magnum heads

[Deaf Bob]

702= 1485 lbs dry.

http://www.6066gmcguy.com/EngineData.html

3 times the weight of a small block chevy for lots of torque and maximum rpm of 2400. 250 hp..

All info needed is in this link.. Including pics of a couple neat looking rigs!

[BigAL]

Magnum heads won't work with the V12 intake, so if I want to use them I would have to do a custom intake.