MuscleCarDynamics

iTrader: (1)

Hi, I figured I should share the L92/4L80E convertion I'm doing on my 1977 crew cab GMC dually. The truck used to have a 350ci SBC with a SM465 transmission but I'm tired of shifting and ready for more power. I use this truck for my shop and do a ton of towing with it. I was going to go with an LY6 but ran into an amazing deal on this L92/4L80E. The motor will stay stock for a little wile at least until I get bored. I'm utilizing the stock radiator and fan shroud with an Avalanche fan and clutch. Here's some pictures of the truck.



The old 350 SBC/SM465 next to the new L92/4L80E

This is the exhaust I'm running, I built it out of some leftover exhaust pieces I had around form past projects.

Here's the engine and trans set in the hole.

thunderwagen

iTrader: (3)

Thats an awesome looking truck man!

MuscleCarDynamics

iTrader: (1)

Thank, it gets a lot of look

c-man405

Hey. I have a 80 c10 and was wondering what you are going to do for the fuel pump? What kind are you going to use? Also what are you doing for the harness?
Thanks carter

MuscleCarDynamics

iTrader: (1)

I used an external walbro 255 fuel pump, later down the road I might put it in the tank but I didn't want to pull the bed off the truck. I am using a PSI harness on this project. This is the first time I've used them and I don't know if I will on my next harness (I hate the plastic wire covering). I've used speartech and the GM performance harnesses and I think I like speartech's the most out of all of them.

MuscleCarDynamics

iTrader: (1)

I tig welded the factory steering box side of the power steering hose to the original L92 power steering pump side. Worked out perfect!

Kingc8r

iTrader: (21)

Do want! Awesome build.

reborn750

I love this build!

MuscleCarDynamics

iTrader: (1)

I got the harness, It's a PSI L92/4L80E harness.


I also got the drive shaft shortened, new slip yoke and new carrier pressed on.

sprech

iTrader: (1)

I always loved these old duallies. I'll be interested how much better the mileage is than the standard 8-10 my old big block square Chevy got.

BudRacing

iTrader: (3)

That's one mean lookin shop rig you've got. LS power FTW!

MuscleCarDynamics

iTrader: (1)

fuel mileage wise I'm expecting it to be close to the denali as the truck really isn't much heavier than it and they get about 14/20mpg

130fe

iTrader: (14)

Looks good Michael! Did you keep the VVT or delete it?

MuscleCarDynamics

iTrader: (1)

Thanks Chris, I kept the VVT but I might up the cam later but Keep it VVT. The VVT cams have great torque.

MuscleCarDynamics

iTrader: (1)

Got it fired up and man does it sound nasty for a VVT cam! Here's a quick video.

BudRacing

iTrader: (3)

Sounds great, what mufflers did you go with? Very clean sound for such a beastly truck. Am I barely making out the word Gibson on those?

MuscleCarDynamics

iTrader: (1)

Yeah, they are Gibson mufflers. I put them on my STS-V but they were way to loud with gutted cats and no resonator so I put the stock mufflers back on an used the Gibson's for this project. LOL

Here's a shot of the exhaust when I had it on the 350

MuscleCarDynamics

iTrader: (1)

It's all buttoned up and even got the AC system hooked up and running again (AC is a must for me living in FL). I did the intake like this to shield the filter form water coming off the tires in the rain as the truck doesn't yet have inner fenders. The trans wasn't shifting and seemed like it was stuck in 2nd gear in default so I sent the ECU and TCU back to PSI and I'll have it back tomorrow.

c-man405

Ok I'm sorry for all the questions.. What did you use for the oil pan and motor/trans mounts? I'm researching for my build sound great by the way !
Thanks again carter

MuscleCarDynamics

iTrader: (1)

No problem, I used the stock truck oil pan and it doesn't hang down. The motor mounts are hooker adapters that put the mounts where they were stock on the sbc and the trans crossmember I unbolted slid back and re-drilled the crossmember holes in the frame.