1970 C20 Cummins project RT

[skchevota]

Hey guys , this c20 has been in my family since 72. It was my dads truck and I have had it since around 1990. He has been named Rolling thunder since around 94. I think it was a room mate that first said it sounded like thunder in the distance with the big block and loud exhaust. So the name stuck .
I had a build thread in 2007 called project rolling thunder, it was the trucks at the time configuration and I was going short bed . It was lifted with a cummins and an nv4500 with a 4x4 swap . Well the market crashed , the kids were little and I just started a business so the project went on stand by for about 11-12 years . Had to sell the cummins and drive train to make ends meet about 10 years ago . So now I have moved shops a few times, built my business, bought a building , did a Reno on it and all this time was a pile of parts in the corner that was onece my truck . So I decided it’s time to make it happen .
I mocked up a few different ideas over the last year or so .

[skchevota]

I was really thinking of going back to it’s roots of 2wd and a big block . I have an 8.1l and 4l80 I built for a Camaro project that I set in and it looks killer . My son had gotten into these trucks now ( my real motivation for getting back on this ) and he likes them low . He has a 68 c20 he is now building , I was really thinking of going low with it . But after mocking it up , it looked cool , but this truck has always been lifted .

[skchevota]

Ok , so I’m writing this from my phone while I should probably be sleeping , since I don’t have many pictures of my truck on here , but I can’t leave you hanging with no pictures. So here is one of the big block sitting in my truck and one of my son, and his 68. I will add some more pictures when I get on my laptop this weekend .

[skchevota]

Got a little done on the engine the other night . I already had most of the long block assembled . I was working on installing the front cover . This is a 2006 common rail , but I didn’t have any of the injection or computer so I decided to p pump it .

[skchevota]

So part of the issue with putting a P7100 pump on a common rail block is the bolt pattern changed , and all the gears on a CR are strait cut , a p pump engine has helical cut gears . I centered and installed the case half and have installed to cam/crank, and oil pump gears . The 5 holes that don’t have bolts in them are the ones that will have to be drilled and tapped to finish bolting up the case

[skchevota]

I was missing the exhaust manifold bolts so I found a stainless stud and nut kit on e bay for like $16

[rowdy11]

Subscribed. Can't wait to see the progress!

[skchevota]

so I guess I should post some pictures of the various ideas i had and mocked up . These are the truck sitting on a 2007 dodge mega cab frame and axles that I shorted the wheel base on . i wasn't happy with how much frame was hanging down. due to the shape of the frame the cab had to sit really high if i wanted to put e regular bed on it. in these pictures it was just a bed side. i was going to have to go up another 2-3 inches to fit a bed floor at normal depth

[cornerstone]

Looks like a clean truck!

[skchevota]

next up I had locating a clean frame . I found a 71 c20 roller with a dana 60, rear leafs and disk brakes. i had the whole thing blasted ad then threw on a coat of primer and chassie spray paint. I set my cab on it to Try out a few ideas to see which way I want to build this beast . Don’t worry I have another truck to bill that I am going to sell when done , so none of the extra parts will go to waist . It is a 67 small window , the way it’s looking is it will go on this frame with the big block and 4l80e . My truck will most likely go on the o7 frame as a short bed with the cummins

[skchevota]

the last picture was mooching up the aam 11.5 rear. i got a little ahead of my self, i was thinking about going low, so first I flipped the rear dana to the top of the leafs , and then took the front springs out .I put the front control arms with a shim in the bump stop to simulate a 4/6 drop. the rims i bolted on were from a customer build i borrowed to see how it would look

[skchevota]

Time for an update . It’s been a while but I have been making progress so I will get you up to speed . I picked up a p7100 pump for the truck , it’s just a 160 HP pump but it won’t be stock of coarse . First I couldn’t resist a test fit to see how it fits . While it was up there it was a good time to put in the 4K governor spring kit

[skchevota]

I also pulled the AFC to install a new fuel plate , and adjust the screws

[skchevota]

Well it’s been a long while since I updated this , a lot has happened . I will try to stay on topic since looking back at my first posts on this thread resemble a bad case of ADHD lol

I finished the basic assembly of the Cummins and started prepping the 2007 frame for the 1970 cab
After a lot of measuring I figured where the cab needed to be in relation with the front axle . Luck has it that the engine mounts appear to be in the correct spot already. It’s like dodge planned on someone doing this !

[skchevota]

Unfortunately I didn’t take a lot of pictures putting the frame together but the basics are , shorten frame , reinforce cuts with fish plates , build front cab mounts , drill holes for rear cab mounts .
The rear mounts lined up exactly on top of the frame cross Member that was originally used for the rear of the dodge cab . This also puts it at exactly at 115” wheel base . So short bed it is ! I used the integrated dodge body bushings and just moved them to the o protists location .
Next I set in the cummins!

[skchevota]

Next I rolled the frame out side and finished painting it so I could install the transmission, exhaust and the rest of the suspension

[skchevota]

You may have noticed that the cummins no longer has the exhaust manifold or turbo on in the last picture.
I originally had a 2nd gen manifold bolted on since they flow a bit better. However the turbo placement put the exhaust outlet right against where the fire wall will be , plus the drain back tube and exhaust would be a pain . So I switched to a 3rd gen manifold so I can use off the shelf exhaust, and drain back tubes , plus it will clear the cab with plenty of room

[skchevota]

Next up is the trans , I am using an NV 4500. I naught a new one from Allstate gear . I opted for the 1 3/8 input . I used a combination of an upgraded nv5600 clutch and a conversion flywheel to get the right offset . The bell going is new from advanced adaptors . It was cheaper than buying a used original . The exhaust is a 4” system for a 2003-2007 dodge , I just didn’t use the extra pipes in the center since my truck is quite a bit shorter . The transfer case is an NP271 Manual shift