Grit dog
Full Access Member
- Joined
- May 18, 2020
- Posts
- 6,970
- Reaction score
- 12,219
- Location
- Auburn, Washington
- First Name
- Todd
- Truck Year
- 1986, 1977
- Truck Model
- K20, C10
- Engine Size
- 454, 350
Wow! That truck is gonna be stunning! Nice work!
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Nice truck! My uncle bought a '77 K20 new that had the SB 400. I wasn't overly impressed with it until I bought a '76 Monte with one stock. It was one of the best Chevy engines I ever owned! I've always liked the '79 & up boxes w/fuel access doors the best also. Nice work, she's gonna be super-nice when you get 'er done!The engine:
Ok, so I already mentioned I found an original 400. Since I'm in California, I need to build it and meet the heavy duty emissions requirements. So, I need to keep the smog pump, air tubes, and PCV valve. No cats and no EGR were on the heavy duty emissions for 1976 K20.
Modifications:
* CARB compliant Edelbrock 1400 (600CFM) carburetor
* AFR 195 street heads (I splurged. These look like jewelry). I hated to paint them, but I'm going for an OE look.
* Edelbrock performer manifold (CARB compliant)
* Mellings roller cam/lifters (with specs similar to CARB compliant cam)
* Eagle rotating assembly (crank, 5.7 rods, hypereutectic pistons, etc..)
* Hedman CARB compliant headers with air tubes.
* While the truck had A/C, it was in terrible shape. Rather than try to piece that back together, I went with Vintage Air, so I mounted the compressor in the stock location.
All done and ready to go. On the engine stand waiting to be installed.
I'm not sure why GM chose to throw the TH350's at the HD trucks. I'm sure you won't be doing any serious off-roading or heavy-duty towing, but I've just seen too many TH350's fail in those bigger trucks. Hopefully it'll treat you right!The transmission/t-case:
Of course, the original set up was the TH350 with the NP203. I'm looking to make this a good driver and don't plan to tow anything heavy or any heavy off-roading, so I really wanted to get the RPMs down on the freeway. I choose to go with a TH700-R4 transmission from Gearstar. I went with their Level 3, just to make it as stout as practical. To make life a bit easier, I sent them the t-case and had them rebuild it while they were building the transmission. They mated the two back together and shipped them as a unit on a crate, ready to install. I do need to work through the mounting of the 4WD gear selector, since it is moved back 2". I need to create some spacers to put it back in the original location. Not a big deal, just a little fab work. Note, I'm very impressed with their work. It took them forever to complete it, but not a big deal in my case and they had good reasons (we were in a pandemic after all).
I think you were referring to the 700R4(?). Yea, I know they are definitely on the delicate side. My personal experience with a 700R4 behind a 400SB has been pretty good for about 20 years in my '57 Chevy. I know its a different beast, but I sure love that overdrive. I'll just have to always keep in mind to treat it nice. Hopefully, Gearstar has done all they can to make it robust.I'm not sure why GM chose to throw the TH350's at the HD trucks. I'm sure you won't be doing any serious off-roading or heavy-duty towing, but I've just seen too many TH350's fail in those bigger trucks. Hopefully it'll treat you right!
Thanks. BTW, sweet C4. My favorite color on a Vette.Very nice sir. What a beautiful thing it is turning into. I’m jealous.
No, the TH350's in the HD 4x4 trucks & Suburban's. They're a great tranny otherwise, but there is a reason they made the tougher TH400. That's just my experience here in the mountains of Montana.I think you were referring to the 700R4(?). Yea, I know they are definitely on the delicate side. My personal experience with a 700R4 behind a 400SB has been pretty good for about 20 years in my '57 Chevy. I know its a different beast, but I sure love that overdrive. I'll just have to always keep in mind to treat it nice. Hopefully, Gearstar has done all they can to make it robust.
Thank you. It’s my favorite one of the ones I own. It’s a 6 speed manual and I love to shift gears.Thanks. BTW, sweet C4. My favorite color on a Vette.