What truck do I have? For the Chevy Gods, Historians and Know it alls

[Snake Eyes USA]

Step Dad says it still needs breaking in. There is a split second of smoke when starting it up. Hums like a lion. We are waiting for customs papers before taking it to DMV. I want this truck back on the road.

Originally Posted by special-K

In prior years GMC had a 1000 model, but in this series of trucks the GMCs were 1500, 2500, and 3500. The Canadian built GMC models were badged differently. They were 910, 920, and 930.

It sounds to me like, and how I read it, the 402 was an unused original crate engine. Therefore, not set up for no lead fuel. I'd either find a reasonable lead additive or just run it. If it starts smoking upon start-up it's time to do the heads. Or, do the heads now and put it all behind you. I'd just run it.

The ethanol thing is something we all have to deal with. Just run Startron in the pump gas, if it's going to sit a lot. The ethanol is not good for in storage. The idea is sooner used = good/longer it sits = bad. The additive helps. I've been fine in my '72 letting it sit about 4 months in winter with nothing added... but I should use something to be safer.