I am looking to put a fuel injected engine in my '79 Chevy 3/4-ton 4x4 Camper Special. I will be using this truck as a daily driver, towing boat and camping. I'd be happy to accomplish 15mpg around town; which obviously I wouldn't be flooring the petal everywhere. I plan on putting 33" tires with a 3"-4" lift.

A local junk yard has a 350 vortec and 4L60E tranny out of a 99 Denali which has 14k miles on it, and due to legal issues has just been able to be released for parting out. It has been sitting for about 4 years now inside a storage unit.

They also have a 2000 gas 6.0L and 4L80E tranny with around 33k miles on it.

I currently have a 203 transfer case, but will be switching to a 208 or newer transfer case when I do the conversion. Any suggestions?

I can get the engines for around the same price. My question is how does the 6.0L compare to the 350 gas mileage wise. I am sure the 350 is enough to pull my boat and whatever I have in the bed, but if the gas mileage will be around the same more power is always better.

I was thinking about passing on the transmissions to opt for a built 700r4. I know I will need to trick the computer to think the electric tranny is connected. I was reading on this forum that I can build my own cable to do this. Anyone have a link to a website that shows how? Opinions on that idea?

I know I will need new motor mounts for the 6.0L, my question is: will I need to make my own or is there a kit that adapts the current motor mounts to work?

Also I have been searching these forums quite a bit and have found people saying the newer chevy motors have a pinging problem. Is this something I need to be worried about?


Any other suggestions/comments more than welcome. Thanks.

 

the 6.0 and 4l80 would be a better combination in my opinion, more power, and probably as good or better fuel economy than the 5.7 vortec. you will want to pull the motor, tranny, wiring harness and computer if you get it. swapping out the 4l80 for a 700r4 would be a big no-no, it would cost a lot of cash to build one to hold the power and weight of the truck, without having any reliability issues. the 4l80 however will be much more reliable as is. im sure you could have someone build motor mounts for you if you couldnt find them anywhere, but they wouldnt be that difficult to fab up anyway. The pinging problem you are referring to is most likely piston slap, some say its common, but i personally haven't seen any LS1 based motors with this problem. It's generally common on cold start ups i believe. Welcome to the forum and feel free to ask for advice.