GM Engine Sizes (was Chevy engines)

[Greg Hermann]

>GMC also had an inline 6 that not a lot of folks
>> remember, a fuzz over 300 CID, which was a serious torque monster, and
>> extremely durable. Did very well in C-gas and D-dragster type NHRA stuff.
>
>This would be the 248-270-302 family, not to be confused with the later
>292 Chevy 6 or the old 707  (215-231-261???) (Stovebolt) for that matter.

And the 302 , if you can find one, makes an absolutely insanely easy and
stout and outrageously torquey swap for an FJ-40 Land Crusher, if anybody
is listening. The old Saginaw SM-420 4 speed tranny (with a 7.1 :1 or
whatever low gear) is a natural mate to it, and there are adapters to
couple this tranny to the Toy transfer case. One of the aftermarket
overdrives (Fairey??) will split the tranny gears almost perfectly.
>
>> Not a lot of people realize that the (later) GMC 307 CID V-6 truck motor
>> was a sawed off 409.
>
>The GMC truck V-6, V-8 and V-12 gas and diesel engines were all 60 degree
>blocks and thus shared nothing from the 348-409 engines.

Not even pistons and rods ??
>
>O, P & Cad used the old 4 speed hydramatic
>> from its inception in the late '40's till the end.
>
>1939 was about the first year for single coupling hydros and 1956 was the
>last year.

And in '55 and '56 it was improved from three planetary gears up to four in
each carrier. Which is why the '55-'56 trannies wer the unit of choice in
the old A-Gas class.

Regards, Greg