V6 in a 1970-72 Jimmy?

[Ed Snyder]

Just to clarify -- you couldn't "order" a 70-72 GMC with a V6 from the factory. You ordered one with a V8 and the dealer would perform an engine swap, removing the V8 and installing the V6 in its place. That's what made the price so high. For that reason, I doubt many buyers had that swap done to brand new trucks. More likely after their V8 wore out.

[1969_CM2590D]

I know in the '60's GM offered a few swap kits for vehicles. One was for the early Chevy II's. No V-8's were allowed by corporate policy for the first couple of years, but an SBC kit was offered during that time for "competition" use. You bought the whole car, straight six and all, plus the kit, plus a new V-8 engine, plus dealer labor. It had to be done this way for the warranty to stick and to be legal for "stock" classes at the strip or track. Maybe the dealer would give you a discount if you were pals. I'd wager by the time you added all the figures up you could have bought a new 283 or 327 Impala coupe (or a Monza Spyder with change left over). These Chevy II's did do well at the strip though...

I dunno, maybe you could have done a COPO for a V-6, Ed? Not that that would have been any cheaper.

[Ed Snyder]

While I'm not aware of any COPO V6s, Dennis, I suppose it was possible back in those days. The factories did entertain some special orders back then. For example, the brochures for GMCs from 60 to 66 don't show 3/4 ton Suburbans or panel trucks being available (they did become available in 1967). But I know for a fact that some do exist, possibly built originally for the military. Anybody out there know more about this?

Exterior paint colors were probably a common special order back then.

[bigblockv6]

The V6 was dropped in the light duty series in March of 1969 period! So you can forget about any fantasies of a COPO V6 from 1970-72, from that point on it was a dealer installed option, As of 1970 GMC light duty trucks were no longer assembled at GMC's Pontiac Michigan plant rather just GM assembly plants, Suburban's and Jimmy's came of Chevrolet assembly lines. GMC's Suburban models starting in 1967 came only available with the ubiquitous small block Chivy V8 and inline six. The GMC dealer in San Francisco where we got our 68 had a 67 K series Suburban in the showroom that was converted over to the V6, this was back in November 1967.

[1969_CM2590D]

Yes, indeed! Mine's a last of the line '69 (that rhymes!) that came out of Baltimore.

[BobBray]

GMC actively marketed the V-6 as a replacement for large gasoline engines in other makes of trucks. Catalogs and spec.sheets exist for some of the more common swaps. One in particular that was pretty common was the 351 or 401 into the White 3000 series cabover. The old White flathead sixes were reliable but not efficient.

OHC Pontiac 6 into a GMC pickup would be interesting

[1969_CM2590D]

I don't want to stray too far here, but along with the Pontiac OHC six, the Buick aluminum 215 is interesting as well. Rover took it over and left it largely unmolested in some ways, but cured many weaknesses- many Buick items will still fit. The last version was 4.6 liters (281 CID) and showed up in Land Rover Discoverys until 2005, so it is likely more available than an OHC 6, as well as being proven in an off road 4x4. It's got a GM heritage as well. The dry weight of 318 lbs makes it quite attractive- that's over 100 lbs. less than any of the "lightweight" Chevy sixes! The Rover versions are strengthened, but still weigh just 375 lbs dry.

The Buick/Rover V8 is probably the most hopped up V8 outside of North America, and the most hopped up V8 worldwide outside of those of the Big Three. You can get lots of stuff for it.